Samuel R. M. Reynolds

Vascular patterns in the human ovary

Abstract A study of vascular patterns in the human ovary has been presented. The vascular system in the human ovary is more complex than that of the rabbit. However, it shows helical spiralling with gradual diminishing diameters in the branches of the main ovarian artery. The function of spiralling in the ovarian branches of the arterial system are (1) adaptation of the vasculature to ovarian growth, and (2) to provide a mechanism for the reduction and regulation within the ovary of blood pressure. A relationship exists between arterial spiral distortion resulting from ovarian cysts, corpora lutea, and the arrangement of the ovarian veins. Characteristics of the ovarian artery and its branches have been described. The relation of the condition of the vessels to ovarian activity and inactivity have been discussed. It is suggested that there is a relation between growth and development of ovarian arterial branches and estrogenic activity in the adult. Evidence is presented to show that branching of the arteries in the ovary from late fetal life to shortly after birth is under the influence of maternal hormones. Observation of the venous vascular tree shows completely different characteristics when compared to the arteries.

A spiral artery in the ovary of the rabbit

Abstract A spiral artery within the hilus of the ovary is demonstrated. It is formed by a helix-type of formation from the ovarian artery as it enters the hilus of the ovary and turns sharply cephalad. Further vascularization of the ovary is accomplished by secondary branches arising from the coils of the spiral artery. The speculative implications of this arrangement of the ovarian circulation are discussed in relation to (a) cyclic or periodic ovarian growth; (b) hemodynamic conditions within the uterus; and (c) to the etiology of ovarian pathology.

Quantitative measurement of reactive hyperemia in human skin

Abstract The immediate object of this study was to establish a simple, reliable technique for the estimation of functional changes in the condition of the smallest blood vessels in human skin. This paper is concerned with the second of two such methods. The first of these, which was reported elsewhere, 1 depends largely upon the contractile sensitivity of the smallest blood vessels of the skin to graded mechanical stimulation; the present method measures the capacity of these vessels to respond by reactive hyperemia to a given period of local ischemia. The fact that the amplitude and duration of the response are dependent largely upon the duration of circulatory stasis was established by Lewis 2 and confirmed by others. 3–5 It appeared, therefore, that a procedure could be devised whereby local ischemia might be maintained for a time just sufficient to elicit a given degree of reactive hyperemia. This would then serve as a measure of the reactive capability of the smallest blood vessels in the skin. The present paper, in recording such a method, notes certain seasonal, individual, and physiologic factors which affect this property of the cutaneous blood vessels and tissues. The uses of such a measure of skin function are several. Its chief value should be to provide a means of estimating how disease, physiologic processes, and therapeutic agents affect the capacity of the skin to yield substances which give rise to reactive hyperemia.

Vascular, Metabolic, and Motility Responses of Uterine Tissue Following Administration of Oestrin

Within 30 minutes after the administration of oestrin to ovariectomized rabbits, a maximal hyperemia of the uterine vascular bed takes place. 1 , 2 , 3 , 4 Rhythmic motility of the myometrium does not commence until about the tenth hour after injection of oestrin, and increases progressively until about the twenty-fourth hour. 5 , 6 , 2 In addition to these two effects, oestrin also raises the metabolic rate of uterine tissue. 7 , 8 , 9, 10 The present experiments were performed to ascertain to what extent the initial hyperemia, rise of metabolic activity of the tissue and motility are related to each other. Two main groups of experiments were performed. In one, the O2 consumption rate was measured in a group of untreated rabbits (3½ to 4 months of age), 5 of which were intact and the remainder of which (21 animals) were ovariectomized for periods ranging from 2 to 15 days. In the second group, the O2 consumption rates were measured at intervals of 5, 10, 18, and 24 hours after a single intramuscular injection of 500 international units of oestradiol to rabbits ovariectomized for 9 to 11 days. The tissues were taken immediately after cerebral concussion. Each uterine horn was slit longitudinally throughout its length. Three segments were taken from each uterus, a tubal and a cervical piece from one horn and a section from the middle of the opposite horn, Oxygen consumption measurements were made in Fenn respirometers at a temperature of 37.5°C. After a 15-minute period of equilibration the chambers were closed and readings were made at 10-minute intervals throughout an hour. The hourly consumption of oxygen per milligram of dried tissue (QO2) was determined for the various pieces of tissue dried to constant weight at 85°C.

Chronic uterine distention and its relation to the end of gestation

Summary At the outset, a review of the local physiologic effects of chronicuterine distention under various hormone conditions is given. It isshown that uterine growth resulting from distention takes place inuntreated, ovariectomized rabbits and in rabbits under the influenceof progestin. When estrin is the predominant hormone, the capacityof the distended uterus to grow is appreciably reduced. With these facts as a basis, analysis is made of Hammond’s data onuterine and fetal weights at different stages of gestation in the rabbit.It is shown that a disproportion exists between the growth incrementsof the fetuses and of the uterus in the last third of pregnancy, theformer growing much more rapidly than the latter. It is furthershown that the reason for the increasing disproportion of these growthrates is due largely if not entirely to an increase in the influence ofthe hormone, estrin. Mention is also made of the fact that estrin isthe hormone demonstrated to have the property of imparting rhythmiccontractility to the uterus. As a consequence of the limitation of thecapacity of the uterus to grow, along with the continued increase inthe size of its contents, it is pointed out that the developing rhythmicuterine contractions are rendered increasingly more efficient and forceful.The theory is advanced, therefore, that these physiologic conditionsare the underlying factors which are essential to the onset oflabor, and the commencement of parturition is the result of a gradualand accelerating convergence of these factors, bringing about nutritionalchanges and an appropriate physical orientation of the fetuses.Finally, the common physiologic basis between these conditions favoringthe onset of labor and those which may be responsible for spontaneousabortion is discussed.

Perspectives in prematurity; physiological approaches to an obstetric problem.

Abstract For the conventional obstetrician, prematurity poses three chief problems. First is recognition and treatment of premature labor; second is the immediate and ultimate care of the premature infant; and third is the real, compelling truth of the statistical aspect of the subject. Prematurity alone ranked as the ninth single cause of human death in the United States in 1945 and there is no reason to suppose that this situation is materially different today. For the physiologist, there are likewise three major problems centering about the larger one of prematurity. These are: (1) the characteristics and control of uterine growth during pregnancy; (2) the provision for the nutrition of the fetus; and (3) the complex question of muscular power for emptying the uterus of its contents at term, and not before. Taken together, these factors comprise the principal elements of what we may call the physiologic process of uterine accommodation of the products of conception. At all times, these elements must be so interrelated and integrated that they provide a uterine environment suited to the needs of the embryo and fetus if it is to develop normally. What, then, are the elements of uterine accommodation?

Chronic Uterine Distention in Progestin-Treated Rabbits.†

Summary Chronic uterine distention in oestrin-treated rabbits results in a reduction of the capacity of the uterus to grow in response to the stimulus of distention.

Anterior Pituitary Therapy and Uterine Motility in the Unanesthetized Rabbit

In earlier experiments 1 , 2 on the action of the ovary-stimulating substance of human urine of pregnancy on uterine motility, it was shown that the contracting uterus of the unanesthetized rabbit either approaches the quiescent state or becomes fully quiescent 5 to 7 hours following a single intravenous injection of this material. This takes place whether or not the ovaries are present and so may happen independently of ovarian tissues which might contribute to the effect. The significance of this finding has not been determined however, and it has never been shown that the action of urine-substance parallels the action of anterior pituitary therapy in its effect on uterine motility as it does in certain respects upon the ovary. The data from the present experiments give this latter information and show that the effect of the injection of fresh saline suspension of anterior pituitary glands of the ox or the injection of alkaline extracts of these glands exactly parallels the effect of the injection of pregnancy urine-substance. Beef anterior pituitary preparations used were of 2 varieties: (1) Fresh saline suspension was made within 4 hours of the death of the animal by triturating the glands in a mortar and using the supernatant fluid either immediately or after standing for 2 to 3 days in the ice box. The amount employed was the fluid obtained from 1 to 3 glands. This was at least 5 to 15 times the m. e. d. for ovulation in a post partum rabbit of medium weight. (2) An alkaline extract of ox pituitaries similar to that described by Bugbee et al. 3 was also used. Since the extracts were not freshly made when employed, the approximate m. e. d. for ovulation was determined at the time each extract was used. 0.1-0.2 cc. in a single intravenous injection regularly elicited ovulation.

Innervation to and Within the Uterus.

In the course of certain experiments it became desirable to know the nature of the distribution of nerve paths from the pelvic plexus to their ultimate destinations in the uterus. Accordingly, we have performed a series of experiments in suitable ovariectomized rabbits. In some of these the parametrium was cut through progressively and the uterus left intact. In others, the uterus was cut first and the parametrium left entire. These experiments showed that when some spot in the middle third of the parametrium is cut, the uterus above the level of section fails to respond to lumbar sympathetic stimulation, even though the uterus itself is still intact. With the parametrium uncut, but the uterus severed, the whole organ still responds to pre-sacral nerve stimulation. Experiments on the essentiality of the utero-vaginal junction (containing the uterine cervical ganglia) were performed. This whole region, including cervices, could be excised without modifying the responses of the uterine cornua when the lumbar sympathetic nerves are stimulated. Section of a selected small region of the parametrium at the level of and close to the site of the cervices, promptly abolishes uterine responses to sympathetic nerve stimulation. In other experiments point stimulation of suitable places on the parametrium was made progressively from the tubal end, caudad. It was found in favorable experiments that the uterus contracts more or less locally, directly opposite the site of parametrial stimulation. This local contraction spreads very slowly in both directions, cephalad and caudad. Our results indicate, therefore, that lumbar motor sympathetic fibers pass close to the utero-vaginal junction and then dip more or less deeply into the parametrium as they pass toward the upper end of the uterus. Along their whole course they give off fibers to the uterus, innervating rather restricted regions, and do not contribute to a widespread, diffuse plexus within the uterine walls.

Action of Pilocarpine and Atropine on Uterine Fistulae in the Unanesthetized Rabbit

The effect of pilocarpine and atropine on the uterine fistula of the unanesthetized rabbit has been observed. The data include observations of 18 injections of pilocarpine and 14 injections of atropine on 5 rabbits over several different days. The method of recording such motility has been described. 1 , 2 Adult female rabbits (albino, chinchilla and brown) were castrated at the time of operation. On the day prior to the experiment, 25-50 r.u. of oestrin (Theelin; Theelol from Parke, Davis and Co.) were administered when marked motility was desired. 3 When quiescence was desired, the castrated rabbit was untreated. 3 The effects noted are as follows: Pilocarpine-HCl. When pre-injection motility is rhythmical in character and of marked amplitude, pilocarpine (0.6-6 mg.) administered intravenously promptly elicits a sustained contraction lasting one to 4 or more minutes. The contractions which follow are frequently of greater duration and increased frequency. The amplitude of these contractions seems not to be regularly affected. When the uterus is relatively quiescent, as recorded by the balloon method, pilocarpine is without effect, or else it elicits a feeble sustained contraction. It is the impression of the observer that when this takes place it occurs in association with other effects of the pilocarpine (cyanosis and pulmonary distress). The non-responsiveness of the quiescent uterine fistula to pilocarpine is similar to its non-responsiveness to posterior pituitary extracts 4 and in anaphylactic shock. 5 Epinephrine, however, does elicit a sustained uterine contraction of the quiescent uterine fistula. Atropine-sulphate. This drug (1-5 mg.) by itself has no observable effect on either the contracting or quiescent uterine fistula. Its action is limited to (a) preventing a response to subsequent administrations of pilocarpine (the duration of this antagonism varied from 9 minutes in one instance to 30 minutes in another); (b) causing relaxation of a uterus already contracted under the influence of pilocarpine.