The present studies were carried out to characterize and compare the acute effects of cage-restraint or administration of a mild anaesthetic on serum levels of testosterone (T) cortisol (C), prolactin (Prl) and bioactive luteinizing hormone (LH) in adult male rhesus monkeys. Serum T levels declined progressively while C levels increased in the 3 sequential blood samples obtained at 20 min intervals from restrained monkeys. Prl and LH levels in the serum remained unaltered. Following single or multiple injections of ketamine hydrochloride (10 mg/kg) serum T levels did not decline progressively as seen in the blood samples obtained from the cage\x=req-\ restrained, conscious monkeys. Serum C and Prl levels showed a progressive rise following anaesthetization. LH levels were not affected by the anaesthetic. The findings reported here are of pertinent relevance to the evaluation of acute effects of any experimental procedure aimed at altering circulating levels of the hormones studied.

Spermatozoan nuclear chromatin is in a highly condensed state prior to fertilization. In vivo decondensation occurs in the ooplasm and is essential for successful fertilization and the formation of male pronucleus and the zygote to occur. The chromatin of spermatozoa and nucleus can undergo in vitro decondensation with sodium dodecyl sulfate (SDS) and 6 mM ethylene diamine tetraacetic acid (EDTA). The ability of sperm to decondense in vitro was compared with their ability to fertilize human oocytes in vitro. Spermatozoa from normal samples were studied for their decondensation ability as regards their fertilizing performance in an in vitro fertilization (IVF) program. Fertilization occurred when the decondensation percentage of sperm nuclear chromatin was more than 70%. The effective sperm count was significantly (p < 0.05) lower in the unfertilized group. This is a new diagnostic technique to assess sperm-fertilizing potential at the initial evaluation of the male.

Six adult lorises (Loris tardigradus lydekkerianus) in anoestrus were selected for study. Four of the animals were pretreated with an injection of 0\m=.\5 mg oestradiol-17\g=b\, two were given FSH (2 \ m=x\ 50 i.u. with a 12-hr interval), while the remaining two were not treated with hormones. All of the animals were subsequently given a subcutaneous injection of 0\m=.\5mCi [3H]thymidine and their ovaries were recovered for autoradiography 24 hr later. It was found that the non-follicular germinal cells within`nests' in the ovarian cortex actively incorporated the radioisotope. Some of the labelled germinal cells appeared to reach the pachytene-diplotene stages of meiotic prophase, although this would not be expected to occur in such a short time after treatment. None of the labelled germinal cells appeared to enter upon the phase of follicular growth, although a few (especially in ovaries treated with oestrogen and FSH) seemed to be in primordial follicles consisting of an incomplete layer of flattened cells.

Certain cells lining a circumscribed area of the III ventricle of the rhesus monkey differ from those cells which constitute the characteristic ependymal lining of the brain. The specialized cells studied comprise a number of types which differ in their structure, ultrastructure and staining affinities; all demonstrate features which are generally associated with active secretion and/or absorption. A group of such cells, which form a limited area of the latero-ventral walls of the anterior hypothalamus, have long processes which extend to the walls of the blood vessels in the median eminence. The evidence indicates that many of these cells, here described as Type B or tanycyte cells, secrete their products into the primary capillary network of the pituitary portal system. Another group of cells, here described as Type C and C' cells are found in a slightly more posterior position lining the floor of the ventricle; as yet there are no indications that these may secrete into blood vessels in the median eminence. Some of the specialized cells lining the III ventricle (Types B and C') showed changes in relation to reproductive activity: No such changes were observed in Type C cells nor in the characteristic ependymal cells (Type A) found elsewhere. Studies on normal and experimental male and female monkeys showed that Type B tanycyte cells differed in males and females and altered during the menstrual cycle in the female. Following ovariectomy these cells showed regressive changes but returned to a normal appearance after a single injection of oestradiol. In view of the close spatial relationship of the tanycyte ependyma to cells of the pars tuberalis it was interesting to note that pars tuberalis cells also altered in relation to the menstrual cycle. The evidence presented accords with the view that certain cells which line the III ventricle of the brain and have prolongations extending to pituitary blood vessels, thus linking the cerebrospinal fluid and the blood system in the region of the pituitary, may play a role in the regulation of pituitary function and thereby constitute an important neuro-endocrine system.

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