Leonardo Vecchiet

The contribution of reactive oxygen species to sarcopenia and muscle ageing

In recent years, age-related diseases and disabilities have become of major interest and importance for health. This holds particularly for the Western community, where the remarkable improvement of medical health, standard of living, and hygiene have reduced the main causes of death. Despite numerous theories and intensive research, the principal molecular mechanisms underlying the process of aging are still unknown. Most, if not all, attempts to prevent or stop the onset of typical degenerative diseases associated with aging have so far been futile. Solutions to the major problems of dealing with age-related diseases can only come from a systematic and thorough molecular analysis of the aging process and a detailed understanding of its causes.

Pain threshold variations in somatic wall tissues as a function of menstrual cycle, segmental site and tissue depth in non-dysmenorrheic women, dysmenorrheic women and men.

Abstract Pain symptoms of many disorders are reported to vary with menstrual stage. This study investigated how pain thresholds to electrical stimulation of the skin, subcutis and muscle tissue varied with menstrual stage in normal women and compared these variations with those in women with dysmenorrhea and in healthy men at matched intervals. Thresholds of the three tissues were measured four times during the course of one menstrual cycle at four sites. Two of the sites were on the abdomen within the uterine viscerotome (abdomen‐rectus abdominis, left and right) and two were outside it on the limbs (leg‐quadriceps, arm‐deltoid). Calculated from the beginning of menstruation (day 0), the menstrual phases studied were menstrual (days 2–6), periovulatory (days 12–16), luteal (days 17–22) and premenstrual (days 25–28). Spontaneous pain associated with menstruation was measured from diary estimates on a VAS scale. Menstrual phase, dysmenorrhea and tissue: Whereas the highest thresholds always occurred in the luteal phase regardless of segmental site or stimulus depth, the lowest thresholds occurred in the periovulatory stage for skin, whereas those for muscle/subcutis occurred perimenstrually. Dysmenorrhea accentuated the impact of menstrual phase. For non‐dysmenorrheic women menstrual trends were significant only in abdominal muscle and subcutis, but for dysmenorrheic women the trends were also significant in abdominal skin and in limb muscle and subcutis. Dysmenorrhea also lowered thresholds mainly in muscle and sometimes in subcutis, but never in skin, with the greatest hyperalgesic effects in left abdominis muscle. Segmental site: Abdominal sites were more vulnerable to menstrual influences than limb sites. Muscle thresholds, but not skin or subcutis thresholds, were significantly lower in abdomen than in limbs, particularly in dysmenorrheic women. The amount of abdominal muscle hyperalgesia correlated significantly with the amount of spontaneous menstrual pain. Sex differences: Only minor sex differences were observed for pain thresholds of the arm and leg, but there was a unanimous refusal by men, but not by women, to be tested at abdominal sites. These results indicate that menstrual phase, dysmenorrhea status, segmental site, tissue depth and sex all have unique interacting effects on pain thresholds, thus adding more items to the lengthy and still‐growing list of biological factors that enter into an individuals judgment of whether or not a stimulus is painful.

Specific oxidative alterations in vastus lateralis muscle of patients with the diagnosis of chronic fatigue syndrome

Chronic fatigue syndrome (CFS) is a poorly understood disease characterized by mental and physical fatigue, most often observed in young white females. Muscle pain at rest, exacerbated by exercise, is a common symptom. Although a specific defect in muscle metabolism has not been clearly defined, yet several studies report altered oxidative metabolism. In this study, we detected oxidative damage to DNA and lipids in muscle specimens of CFS patients as compared to age-matched controls, as well as increased activity of the antioxidant enzymes catalase, glutathione peroxidase, and transferase, and increases in total glutathione plasma levels. From these results we hypothesize that in CFS there is oxidative stress in muscle, which results in an increase in antioxidant defenses. Furthermore, in muscle membranes, fluidity and fatty acid composition are significantly different in specimens from CFS patients as compared to controls and to patients suffering from fibromyalgia. These data support an organic origin of CFS, in which muscle suffers oxidative damage.

Artificial ureteral calculosis in rats: behavioural characterization of visceral pain episodes and their relationship with referred lumbar muscle hyperalgesia

&NA; In a rat model of artificial ureteral calculosis, the aim of the study was to characterize the behavioural manifestations of direct visceral pain and to evaluate the relationship between number, duration and complexity of the visceral episodes and the extent of referred lumbar muscular hyperalgesia. As evidenced by non‐stop video‐tape recordings over 4–14 days, almost 98% of stone‐implanted rats showed episodes similar to the writhing behaviour characteristic of noxious visceral stimulation in animals. From one rat to another, these episodes varied from very few (1–3) to a very high number (± 60), lasted a few minutes to over 45 min and were of variable complexity, as evaluated via an arbitrary scale on the basis of the combination of movements. Their number and duration decreased significantly, in a linear fashion, as time passed after the operation, so that they were mostly concentrated during the first 3 days. Number, duration and complexity of episodes were reduced by chronic treatment with morphine in a dose‐dependent fashion. Stone‐implanted rats displaying visceral episodes also showed hyperalgesia of the ipsilateral oblique musculature, as evidenced by a decrease in the vocalization threshold to electrical muscle stimulation, which was maximum on the first 3–4 days after implantation but lasted up to 10 days. The visceral episodes and the muscle hyperalgesia showed a strict relationship of interdependence: a significant, direct linear correlation was found between number and duration of episodes and degree of ipsilateral muscle hyperalgesia; such a correlation was also found between degree of complexity of episodes and tendency to also develop a contralateral muscle hyperalgesia. By applying the results of the study to the interpretation of human pathology, referred lumbar muscle hyperalgesia from ureteral calculosis would appear to be a strict function of the colic pain experienced.

Age and sex influence on oxidative damage and functional status in human skeletal muscle

A reduction in muscle mass, with consequent decrease in strength and resistance, is commonly observed with advancing age. In this study we measured markers of oxidative damage to DNA, lipids and proteins, some antioxidant enzyme activities as well Ca2+ transport in sarcoplasmic reticulum membranes in muscle biopsies from vastus lateralis of young and elderly healthy subjects of both sexes in order to evaluate the presence of age- and sex- related differences. We found a significant increase in oxidation of DNA and lipids in the elderly group, more evident in males, and a reduction in catalase and glutathione transferase activities. The experiments on Ca2+ transport showed an abnormal functional response of aged muscle after exposure to caffeine, which increases the opening of Ca2+ channels, as well a reduced activity of the Ca2+ pump in elderly males. From these results we conclude that oxidative stress play an important role in muscle aging and that oxidative damage is much more evident in elderly males, suggesting a gender difference maybe related to hormonal factors.

Influence of endometriosis on pain behaviors and muscle hyperalgesia induced by a ureteral calculosis in female rats.

&NA; Endometriosis and urinary calculosis can co‐occur. Clinical studies have shown that both painful and non‐painful endometriosis in women are associated with enhanced pain and referred muscle hyperalgesia from urinary calculosis, but the mechanisms underlying this phenomenon are still poorly understood. The aim of this study was to develop an animal model adequate to explore this viscero‐visceral interaction in standardized conditions. Using a model of endometriosis previously developed to study reduced fertility and vaginal hyperalgesia, endometriosis (endo) or sham‐endometriosis (sham‐endo) was induced in rats by autotransplantation of small pieces of uterus (or, for sham‐endo, fat) on cascade mesenteric arteries, ovary, and abdominal wall. After the endometrial, but not the fat autografts had produced fluid‐filled cysts (3 weeks), urinary calculosis was induced by implanting an artificial stone into one ureter. Pain behaviors were monitored by continuous 24‐h videotape recordings before and after stone implantation. Referred muscle hyperalgesia was assessed by measuring vocalization thresholds to electrical stimulation of the oblique musculature (L1 dermatome). The data were compared with previously reported data from rats that had received only the stone. Neither endo nor sham‐endo alone induced pain behaviors. Following stone implantation, in endo rats compared to sham‐endo and stone‐only rats, pain behaviors specifically associated with urinary calculosis were significantly increased and new pain behaviors specifically associated with uterine pathology became evident. Muscle hyperalgesia was also significantly increased. To explore the relationship between the amount of endometriosis and that of ureteral pain behavior, two separate groups of endo rats were treated with either a standard non‐steroidal anti‐inflammatory drugs (ketoprofen) or placebo from the 12th to the 18th day after endometriosis induction. The stone was implanted on the 21st day. Ketoprofen treatment compared to placebo significantly reduced the size of the cysts and both ureteral and uterine pain behaviors post‐stone implantation. The size of the cysts showed a significant linear correlation with the post‐stone ureteral pain behaviors. In conclusion, endo increased pain crises and muscle hyperalgesia typically induced by a ureteral calculosis, and the ureteral calculosis revealed additional pain behaviors typically induced by uterine pathophysiology; and this enhancement was a function of the degree of endometriosis. This result closely reproduces the condition observed in humans and could be due to a phenomenon of ‘viscero‐visceral’ hyperalgesia, in which increased input from the cyst implantation sites to common spinal cord segments (T10‐L1) facilitates the central effect of input from the urinary tract.

Pain from renal/ureteral calculosis: evaluation of sensory thresholds in the lumbar area.

&NA; Patients with unilateral renal/ureteral calculosis who had suffered a few painful attacks were examined. In the pain‐free period, muscular, subcutaneous and cutaneous sensory thresholds to electrical stimulation were measured in the lumbar region (metamer L1) on both sides: (1) pain thresholds were lower on the affected side with respect to both the contralateral side and control thresholds recorded in normal subjects; (2) the greatest decrease in threshold was in the muscle (even the sensation of sustained contraction was no longer detectable), followed by subcutaneous tissue, and the smallest decrease was in the skin.

Changes in visceral pain reactivity as a function of estrous cycle in female rats with artificial ureteral calculosis

This study examined estrous differences in the characteristics of behavioral crises of visceral pain in female rats video-taped throughout a 4-day period after implantation of an artificial stone in one ureter. All animals continued to have a regular cycle after ureteral surgery. In the recording period, the percentage of time spent in crises was significantly higher during metestrus/diestrus (M/D) than during proestrus/estrus (P/E) (P < 0.001, chi2-test). Mean duration and complexity of crises were slightly higher in M/D than in P/E, but the difference was not significant. The results in this animal model show an enhancement of ureteral pain sensitivity in M/D, a finding in line with the clinical observation, in fertile women with urinary calculosis, of a greater incidence of colics in the perimenstrual period (equivalent to M/D in rats).

Effects of extracorporeal shock-wave lithotripsy on referred hyperalgesia from renal/ureteral calculosis

&NA; In patients suffering from colics due to calculosis of one upper urinary tract the evolution in time of referred parietal hyperalgesia after stone fragment elimination promoted by extraeorporeal shock wave lithotripsy (ESWL) was studied. Before ESWL, all patients presented clinical evidence (positivity to dermographism and Heads procedure, pinch palpation, digital pressure and Giordanos manoueuver) and instrumental signs (significant lowering of pain threshold to electrical tissue stimulation) of cutaneous, subcutaneous and muscular tissue hyperalgesia in the lumbar region of the affected side. After ESWL, hyperalgesia decreased in the three tissues, as shown by progressive change in the clinical tests and an increase in pain threshold to electrical stimulation in relation to the extent of stone fragment expulsion. In the stone‐free condition, hyperalgesia had disappeared in the skin but remained to a mild and moderate extent in the subcutaneous tissue and muscle respectively. It is concluded that the persistence in time of referred hyperalgesia is only in part linked to the continuing presence and activity of the stone in the urinary tract. To a certain extent, the phenomenon seems to become independent of the primary focus, possibly as a result of plastic neuronal changes in the central nervous system which, triggered by afferent visceral inputs, are maintained even after their removal.

Modulation of pain and hyperalgesia from the urinary tract by algogenic conditions of the reproductive organs in women.

This study investigated the impact of algogenic conditions of the reproductive organs upon urinary pain perception in women. A 5-year survey was conducted among 69 fertile women with calculosis of one upper urinary tract via an ad-hoc questionnaire. At both retrospective (3 years) and prospective (2 years) investigation, dysmenorrheic women (D) reported more colics than non-dysmenorrheic women (ND) (P<0.001) and women with previous dysmenorrhea treated with estroprogestins (DH)(P<0.05). Pain thresholds (electrical stimulation) of the oblique musculature ipsilateral to the stone (L1, site of referred hyperalgesia from upper urinary tract) were lower in D than in ND (P<0.01) and DH (P<0.05). Calculosis women with asymptomatic endometriosis / ovarian cysts also reported more colics (6-month prospective study) and greater threshold lowering (P<0.05) than women with calculosis alone. The results show enhancement of urinary pain / hyperalgesia by both manifest and latent algogenic conditions of the female reproductive organs. This enhancement could derive from neuronal sensitization in spinal segments of common projection of the two visceral districts (T10-L1).