Jorge Rodríguez-Antolín

Multiparity causes uncoordinated activity of pelvic- and perineal-striated muscles and urodynamic changes in rabbits.

Temporal and coordinated activation of pelvic- (pubococcygeous) and perineal- (bulbospongiosus and ischiocavernosus) striated muscles occurs during micturition in female rabbits. We have hypothesized that the coordinated activation of pelvic and perineal muscles is modified during the micturition of young multiparous rabbits. Young virgin and multiparous female chinchilla rabbits were used to simultaneously record cystometrograms and electromyograms of the pubococcygeous, ischocavernosus, and bulbospongiosus muscles. Bladder function was assessed using standard urodynamic variables. The temporal coordination of pelvic- and perineal-striated muscle activity was changed in multiparous rabbits. The cystometrogram recordings were different than those obtained from virgin rabbits, as seen in alterations of the threshold volume, the residual volume, the voiding duration, and the maximum pressure. In rabbits, we find that multiparity causes uncoordinated activity of pubococcygeous, ischiocavernosus, and bulbospongiosus muscles and modifies the urodynamics.

Association between the serum concentration of triiodothyronine with components of metabolic syndrome, cardiovascular risk, and diet in euthyroid post-menopausal women without and with metabolic syndrome

PurposeTo determine the association between the serum concentration of triiodothyronine (T3) with components of metabolic syndrome (MetS), cardiovascular risk (CVR), and diet in euthyroid post-menopausal women without and with MetS.MethodsA cross-sectional study was performed in 120 voluntary women of an indigenous population from Tlaxcala-México. Euthyroid status was assessed measuring the serum concentration of thyrotropin (TSH) and thyroid hormones, while that of estradiol was measured to confirm the postmenopausal condition. MetS was diagnosed using the American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement (AHA/NHLBI) criterion. Estimation of CVR was calculated based on the Framingham scale. Diet components were evaluated based on survey applications. Correlations, logistic regression analyses, ANOVA or Kruskall-Wallis, and chi-square tests were used to determine significant differences (P ≤ 0.05) between women without MetS and women with MetS having different serum concentrations of T3.ResultsTriiodothyronine was positively correlated with insulin but negatively correlated with glucose, high-density lipoprotein cholesterol (HDL-C), and CVR. Compared to women without MetS, women with MetS and low-normal T3 concentration showed a high risk for hyperglycemia and moderate/high risk for CVR. In contrast, a high-normal T3 concentration increased the risk to have a big waist circumference, a high concentration of HDL-C, and insulin resistance. Diet analysis showed a high grade of malnutrition in women from all groups. The intake of calories was positively affected by the T3 concentration, albeit it did not affect the extent of malnutrition.ConclusionsIn contrast to concentrations of TSH, total thyroxin (T4), and free T4, the concentration of serum T3 was strongly correlated with cardio-metabolic variables in euthyroid postmenopausal women. In comparison to women without MetS, a high-normal serum concentration of T3 in women with MetS is positively associated with reduced glycaemia and CVR but negatively related to body mass index (BMI), insulin, insulin resistance, and HDL-C. Although the analyzed population had a nutritional deficiency, both calories and iron intake were positively affected by the T3 concentration. Our results suggest the necessity of health programs monitoring T3 in old people in order to treat hyperglycemia, cardio-metabolic components, and the ageing anorexia.

General tissue characteristics of the lower urethral and vaginal walls in the domestic rabbit.

In European rabbits, the distal urethra (DU) opens into the anterior pelvic vagina forming a single canal by which females copulate, give birth, and urinate. We investigated whether the histological characteristics of the DU and the pelvic and perineal vagina are different. The DU and vagina of rabbits (Oryctolagus cuniculus) were cut and stained with hematoxylin–eosin and Masson’s trichrome (n = 3). Data were compared by using Friedman’s ANOVA for repeated measures. The walls of the DU and vagina are composed of mucosa, submucosa, smooth muscle, and an external layer. Differences in tissue characteristics of the mucosa, orientation of the smooth muscle fibers, components of the external layer (connective tissue, blood vessels, and striated musculature), and thickness of the tissue layers were found among regions. The lack of histological homogeneity along the urethra and vagina possibly reflects differences in the functions of each segment.

Morphometry of paravaginal ganglia from the pelvic plexus: impact of multiparity, primiparity, and pregnancy

OBJECTIVES (1) To describe the morphology of paravaginal ganglia and the neurochemical pattern of their neurons in virgin rabbits. (2) To analyze the effects of multiparity, primiparity and late pregnancy on morphometry of ganglia and their neurons. STUDY DESIGN The morphology and neurochemical pattern of paravaginal ganglia were described in virgin nulliparous Chinchilla breed rabbits. Acetylcholinesterase histochemistry, Massons trichrome, and immunohistochemistry for cholinergic and adrenergic neurons, and estrogen receptors (ERs) were undertaken. The area covered by ganglia (ganglionic area), the number of neurons, and the neuron soma area were measured in multiparas (4 consecutive and successive deliveries) and age-matched nulliparas. The same variables were measured in primiparous, late-pregnant, and age-matched nulliparous rabbits. RESULTS Paravaginal ganglia were adjoined to the dorsolateral walls of the pelvic vagina. Their neurons were mostly cholinergic and expressed ERα and ERβ. Multiparity increased the ganglionic area and reduced the number of ganglionic neurons. Late pregnancy transiently reduced the neuron soma area, which was coincident with a low expression of ERs. CONCLUSION Multiparity but not primiparity affected the morphometry of ganglia. The hormonal state present in late pregnancy alters the neuron soma area and ER expression. Our findings support the notion that reproduction influences the morphometry of the pelvic plexus.

Components of the neural circuitry of the vaginocavernosus reflex in rabbits

In mammals the mechanisms underlying female sexual and reproductive biology are poorly understood. Little attention has been paid to striated muscles and their neural regulation. The aim of the present study was to describe the components of the vaginocavernosus reflex in adult rabbits. It was found that mechanical stimulation of the glans of the clitoris and the perineal vagina induced electromyographic (EMG) responses in bulbocavernosus (Bcm) and ischiocavernosus (Icm) muscles. Unilateral and bilateral nerve transection indicated that the clitoral nerve is the main afferent path of the reflex and that it recruits ipsilateral and contralateral perineal motoneurons. Injection of horseradish peroxides‐wheat germ agglutinin (HRP‐WGA) into the Bcm and Icm labeled spinal motoneurons scattered in L7 and S1 segments. According to the results of this study and previous work, the elements of the vaginocavernosus reflex may be described as follows. Mechanical receptors are located in the glans clitoris and in the wall of the perineal vagina. The main afferent pathway is the clitoral nerve. It activates ipsilateral and contralateral Bcm and Icm motoneurons in lumbosacral segments. Axons of efferent neurons travel through the clitoral and ischiocavernosus nerves, and the effectors are the Bcm and Icm perineal muscles. Identification of neural components of the vaginocavernosus reflex in rabbits will allow the use of this animal as a model to assess the physiological characteristics of the perineal motoneurons as well as the contribution of the Bcm and Icm in female urogenital functions. J. Comp. Neurol. 518:199–210, 2010.

Tissue alterations in urethral and vaginal walls related to multiparity in rabbits.

In rodents, vaginal distention after delivery or experimental manipulation affects innervations as well as the amount of striated/smooth musculature or collagen in both the urethra and vagina. These changes are associated with modifications in excretory and reproductive processes. Although successive and consecutive vaginal deliveries (multiparity) affect the contractile and functional properties of the female lower urogenital tract (LUT), its impact on LUT morphometry, including persistency, has been barely studied. The caudal urethra (CU) and cranial (V1) and caudal (V2) pelvic vaginal regions were excised from young and adult nulliparous (YN and AN, respectively) and multiparous (YM and AM, respectively) rabbits. Tissues were histologically processed and stained with Massons trichrome. The thickness of the tissue layers and areas covered by tissue components were measured and compared using two‐way ANOVA followed by Student‐Newmann‐Keuls tests to determine statistical differences (P ≤ 0.05). Compared to YN, YM, and AN tissues showed a reduction in the thickness of the epithelium, as well as in areas covered by striated musculature, collagen, and blood vessels of the LUT. In comparison with YM, only some morphometric changes were recovered in the AM group. Our study shows that multiparity and age can be associated with epithelial and muscular atrophy of urethral and vaginal walls. The morphometry of the LUT between young and adult female rabbits varies with multiparity. These findings may help to better understand the effects of multiparity on young and adult females and its correlation with the development of pelvic dysfunctions. Anat Rec, 297:1963–1970, 2014.

Morphological characteristics of the cervix in domestic sows

Artificial insemination is commonly practiced in several domestic animals, including sows. Postcervical insemination is used to increase the fertility index, given that the volume of semen is optimized. Knowledge of the anatomical and physiological characteristics of the genital tract can be used to improve our understanding of the fertilization process that occurs during artificial insemination, and possibly to improve the technique. The aim of our study was to examine the gross morphology and histological properties of the cervix of recently slaughtered multiparous sows, using different stains. The results indicate that the porcine cervix has two regions: a uterine region characterized by the presence of glandular acini, and a vaginal region with a large vascular network. Both regions showed a mixed secretory activity by epithelial cells, which produced sulfated mucins (mucous secretion), intermingled with abundant glycogen-rich cells (serous secretion). This study contributes to the understanding of the morphologic features of the porcine cervix.

Interactive effects of chronic stress and a high-sucrose diet on nonalcoholic fatty liver in young adult male rats

Abstract Glucocorticoids have been implicated in nonalcoholic fatty liver diseases (NAFLD). The influence of a palatable diet on the response to stress is controversial. This study explored whether a high-sucrose diet could protect from hepatic steatosis induced by chronic restraint stress in young adult rats. Male Wistar rats aged 21 days were allocated into four groups (n = 6–8 per group): control, chronic restraint stress, 30% sucrose diet, and 30% sucrose diet plus chronic restraint stress. After being exposed to either tap water or sucrose solution during eight weeks, half of the rats belonging to each group were subject or not to repeated restraint stress (1 h per day, 5 days per week) during four weeks. Triacylglycerol (TAG), oxidative stress, activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1), infiltration of immune cells, and glycogen amount in the liver were quantified. Serum concentrations of corticosterone and testosterone were also measured. The stressed group showed normal serum concentrations of corticosterone and did not have hepatic steatosis. However, this group showed increased glycogen, inflammation, mild fibrosis, oxidative stress, and a high activity of 11β-HSD-1 in the liver. The group exposed to the high-sucrose diet had lower concentrations of corticosterone, hepatic steatosis and moderate fibrosis. The group subject to high-sucrose diet plus chronic restraint stress showed low concentrations of corticosterone, hepatic steatosis, oxidative stress, and high concentrations of testosterone. Thus, restraint stress and a high-sucrose diet each generate different components of nonalcoholic fatty liver in young adult rats. The combination of both the factors could promote a faster development of NAFLD.

The Role of Pelvic and Perineal Muscles in Reproductive and Excretory Functions

Excretory and reproductive functions are underlaid by autonomicand somatic-neural control that regulates the pelvic and the perineal structures in mammals. Viscera and striated and smooth muscles are involved in complex and multiple reflexes occurring in the pelvic cavity (Komisaruk and Sansone, 2003; Pacheco et al., 1989; Thor and de Groat, 2010). In women, this region must accommodate the growing fetus during pregnancy and the passage of the newborn during childbirth (Ashton-Miller & DeLancey, 2007). For this to occur, the fetal head has to undergo a series of internal translations and rotations, aided by the maternal effort in the form of active pushing and uterine contraction (Li et al., 2010). Functions, such as urination and defecation, are also regulated by the different autonomic and somatic reflexes of the pelvic cavity. During pregnancy and parturition, the fetal weight, translations, and rotations on pelvic structures, such as pelvic and perineal floor muscles, cause injury to the components of the pelvic reflexes (Kearney, 2006; Lanzarone & Dietz, 2008). This has been associated with visceral disorders, such as pelvic-organ prolapse and urinary and fecal incontinence (Ashton-Miller & DeLancey, 2007; Smith et al., 1989). One of the techniques frequently used to evaluate the participation of pelvic and perineal muscles during normal and pathological functions is electromyography. The electromyographic (EMG) recordings are extremely useful to evaluate the participation of pelvic and perineal muscles during the normal and pathological functions of this female anatomy. The goal of our chapter is to review the literature of the activity of pelvic and perineal muscles and the several viscerosomatic reflexes involved in sexual response and urination in female mammals. Measurements of the pelvicand perineal-muscle EMGs in laboratory rabbits, focusing on methods and results, and the alterations of their activity associated with dysfunctions, particularly with urinary incontinence, will be also reviewed.

Hypothyroidism affects lipid and glycogen content and peroxisome proliferator-activated receptor δ expression in the ovary of the rabbit

Dyslipidaemia and hyperglycaemia are associated with ovarian failure and both have been related to hypothyroidism. Hypothyroidism promotes anovulation and ovarian cysts in women and reduces the size of follicles and the expression of aromatase in the ovary of rabbits. Considering that ovarian steroidogenesis and ovulation depend on lipid metabolism and signalling, the aim of the present study was to analyse the effect of hypothyroidism on the lipid content and expression of peroxisome proliferator-activated receptor (PPAR) δ in the ovary. Ovaries from female rabbits belonging to the control (n=7) and hypothyroid (n=7) groups were processed to measure total cholesterol (TC), triacylglycerol (TAG) and glycogen content, as well as to determine the presence of granules containing oxidized lipids (oxysterols and lipofuscin) and the relative expression of perilipin A (PLIN-A) and PPARδ. Hypothyroidism increased TC and glycogen content, but reduced TAG content in the ovary. This was accompanied by a reduction in the expression of PLIN-A in total and cytosolic extracts, changes in the presence of granules containing oxidative lipids and low PPARδ expression. The results of the present study suggest that hypothyroidism modifies the content and signalling of lipids in the ovary, possibly affecting follicle maturation. These results could improve our understanding of the association between hypothyroidism and infertility in females.