Rete testis fluid contains a growth factor for cultured fibroblasts.
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Animals↗
Biomedical subjects
B P Setchell
Publications and source records attributed to B P Setchell.
The flow and composition of lymph from the testes of pigs with some observations on the effect of raised venous pressure.
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Animals↗
A comparative study of carnitine and acylcarnitine concentration in semen and male reproductive tract fluids.
1. L-carnitine and its short-chain acyl derivatives were measured in semen of boar, man, rooster, bull, squirrel monkey and ram. 2. Carnitine was present in concentrations of 220, 476, 540, 1880, 3330 and 3820 muM respectively, and acetylcarnitine concentrations were 2, 191, 354, 709, 259 and 2750 muM. Propionyl and C4-acyl carnitines were found in small quantities. 3. Analysis of sequential "Split-ejaculate" samples of boar semen showed that carnitine concentration correlated with sperm count, suggesting an epididymal origin for this substance in this species. 4. Bioautographic analysis of samples obtained from ram and rat indicated that carnitine and acetylcarnitine were present in epididymal fluid and in fluids from accessory glands of the male reproductive tract.
Animals↗
Influence of androgens on inositol secretion and sperm transport in the epididymis of rats.
The effects of unilateral efferent duct ligation, bilateral castration or testosterone replacement on the spermatocrit and inositol concentrations in luminal fluid removed by micropuncture from the rat epididymis were investigated. By 5 days after efferent duct ligation, there were substantial falls in the spermatocrit in the caput and corpus, but no change in the cauda. After 7 days there was an increase in the spermatocrit in the cauda. After castration there were more marked reductions in the spermatocrit in the caput and corpus but there was no change in the cauda. The spermatocrit in the corpus, but not in the caput, remained normal when castrated animals were treated with testosterone. The inositol concentrations in luminal fluid from all three sites were not changed after ligation of the efferent ducts but were greatly reduced after castration; this fall was prevented by testosterone treatment. The results support the suggestion that inositol is secreted in the rat epididymis and also indicate that the secretory process is controlled by androgens.
Androgens↗
Secretion of free and conjugated steroids by the horse testis into lymph and venous blood.
In 3 testes of 2 adult Pony stallions under halothane anaesthesia, catheters were inserted into a vein and a lymphatic vessel in the spermatic cord and into a vein on the surface of the testis. Lymph and venous blood were collected from the catheters in the cord and p-aminohippurate (2% w/v, 0 . 1 ml/min) was infused into the vein on the testis to determine blood flow by dilution. After 1 h, 6000 i.u. hCG was injected i.v. and collections continued for 45 min. The testes weighed 126-176 g. Lymph flow was 20-150 microliter/min before hCG and 100-270 microliter/min after hCG; the range of blood flow, with a haematocrit of about 22%, was unchanged (27-47 ml/min) after hCG. The concentration of testosterone in spermatic venous blood rose from 6-20 ng/ml to 160-270 ng/ml within about 30 min after hCG. Peripheral levels rose from about 2 to 6 ng/ml and lymph levels increased from 9-20 to 34-150 ng/ml after hCG. In contrast, the concentrations of oestrone sulphate in spermatic venous blood were about 400 ng/ml, compared with about 250 ng/ml in peripheral blood, while lymph values ranged from 600 to 1500 ng/ml; hCG had no consistent effect. DHA and its sulphate were present in spermatic venous blood at concentrations (about 3 and 5 ng/ml respectively) slightly higher than in peripheral blood (1 . 7 and 2 . 5 ng/ml), but the sulphate was at a very much higher concentration in lymph (about 5 and 200 ng/ml respectively). These results indicate that testicular lymph is an important route for the secretion of conjugated steroids by the horse testis.
Animals↗
Labelling of membrane glycoproteins on rat spermatozoa collected from different regions of the epididymis.
The major glycoprotein on the plasma membrane of testicular spermatozoa labelled with the galactose oxidase/NaB3H4 technique has mol.wt. 110 000. As spermatozoa pass through the epididymis, labelling of this glycoprotein disappears and is replaced by labelling of a 32 000-mol.wt. protein. The latter protein is a major component of epididymal secretions. The evidence suggests that it is inserted into or absorbed on to the plasma membrane, and since its appearance on spermatozoa correlates with the acquisition of fertilizing capacity it should serve as a good marker for assessing maturation in vitro.
Animals↗
The concentration of some inorganic ions and organic compounds in the luminal fluid of the human ductus deferens.
The concentrations of some inorganic ions (sodium, potassium, chloride and phosphate) and organic compounds (carnitine, myo-inositol, glycerophosphocholine, phosphocholine and total phosphate) were estimated in the luminal fluid collected from sections of human ductus deferens removed at vasectomy. From the data presented it would appear that in contrast to non-primate species, in the human the inorganic ions contribute more to the total osmolarity of the luminal fluid than do the organic compounds.
Adult↗
The utilization of lactic acid by sheep in late pregnancy.
The irreversible loss of lactate and the respiratory exchange in four conscious ewes that were about 138 days pregnant were measured at least seven days after surgery. In addition, the uptake and net output of lactate and the net uptake of glucose and alanine by the gravid uterus and an upper hind limb (primarily skeletal muscle) were measured. Calculated heat production of the ewes was 496 kJ/d.kg 3/4; irreversible loss of lactate was 9.5 mumol/min.kg of which 73% was oxidized to CO2, contributing 9% to the ewes' CO2 production. About 2% of the glucose and 65% of the alanine was derived from lactate. Lactate was taken up by both the gravid uterus and the upper hind limb; output of lactate could have accounted for from 8-12% of glucose uptake by the gravid uterus but from 35-50% of that by the upper hind limb. The carbohydrate/O2 quotient was 1.07 for the gravid uterus and 0.35 for the upper hind limb.
Alanine↗
Effects of carnitine and some related compounds on the motility of rat spermatozoa from the caput epididymidis.
Spermatozoa were collected from the rat caput epididymidis by micropuncture and their motility assessed after dilution in physiological saline containing carnitine or related compounds. L(+)-Carnitine caused, 2 min after dilution, a transient stimulation of the motility of spermatozoa with low initial motility. No stimulatory effects were seen on spermatozoa which had high initial motility. The D-isomer inhibited the motility of spermatozoa with high initial motility after 2 min and all compounds tested appeared to inhibit, at 20 min after dilution, the motility of spermatozoa with high initial motility. Acetyl-L-carnitine and acetyl-D-carnitine stimulated the motility of spermatozoa with low initial motility. This study suggests that carnitine may be important in the development by spermatozoa of the potential for motility and also to maintain mature spermatozoa in a quiescent state.
Acetylcarnitine↗
Frequency and duration of the stages of the cycle of the seminiferous epithelium of the nine-banded armadillo (Dasypus novemcinctus).
The majority of the cross-sections of seminiferous tubules of nine-banded armadillos show only one type of cellular association as in most eutherian and metatherian mammals with scrotal testes. The spermatogenic cycle was divided into 8 stages, in relation to the shedding of the spermatozoa. The relative frequencies (%) of stages 1-8 were, respectively: 16.6, 7.5, 12.9, 9.1, 9.7, 18., 11.7 and 13.6. The duration of the cycle was 8.15 days, as determined by intratesticular injection of [3H]thymidine and removing the tissue at different times after injection.
Animals↗
Effects of obstruction of the flow of seminiferous tubule fluid on the germinal epithelium in the rat.
Blocking the lumen of a single seminiferous tubule by introducing a plug of non-toxic latex produced a lesion in that tubule, but not in immediately adjacent tubules. The lesion extended for up to 50 mm from the end of the latex. Nearest to the block the tubule was completely aspermatogenic; further along the tubule, the lesion was less severe, involving disorganization and reduction in germ cell numbers, with the cells showing vacuolation, pycnosis and karyolysis. Binucleate and giant cells were common, and cells were often exfoliated into the lumen. The lesion tended to increase in length with longer times after introduction of the plug, but there appeared to be no preferential involvement of the shorter segment of the tubule between the block and the rete. The transition from damaged to healthy tubule was abrupt.
Animals↗
Effect of injected human chorionic gonadotrophin on capillary permeability, extracellular fluid volume and the flow of lymph and blood in the testes of rats.
The subcutaneous injection of human chorionic gonadotrophin (HCG) into adult male rats caused appreciable rises in capillary permeability and lymph flow in the testis, accompanied by smaller rises in the volume of extratubular, extracellular fluid. Most of these changes were already apparent 8 h after injection, but became progressively greater during the next 12 h. Testicular blood flow was unchanged at 12 h but increased slightly between 12 and 6 h after injection. The primary effect is probably the increase in capillary permeability. The timing of these changes suggests that HCG does not affect the capillaries directly, but it would seem that the changes are due to some substances secreted by the testis in response to the HCG. It is clear that these changes will have important influences both on the access to the testicular cells of peptide hormones in the blood and also on the passage into the venous blood of hormones secreted by the testis.
Animals↗
A simple device for measuring nanolitre volumes of fluid.
A piece of apparatus designed to measure nl-volumes of fluid has been constructed to fit into a Leitz micromanipular so that the small sample volumes can easily be transferred.
Animals↗
Concentrations of myo-inositol in the luminal fluid of the mammalian testis and epididymis.
The concentration of free myo-inositol was measured in the luminal fluid removed by micropuncture from the testis and epididymis of rat, hamster, rabbit, rhesus monkey, baboon, ram and boar. The highest concentration (mM) was found in the epididymal luminal fluid from the cauda epididymidis of the hamster (90) and the rat (50), and the lowest was seen in the rabbit (< 0.5), and boar (1.0-1.2), whilst the rhesus monkey (17), the baboon (1.3) and the ram (0.9-5.9) were intermediate. The species also differed with respect to the changes in luminal inositol coicentration along the epididymis.
Animals↗
Concentrations of glycerophosphocholine, phosphocholine and free inorganic phosphate in the luminal fluid of the rat testis and epididymis.
Measurements were made on micropuncture samples of luminal fluids. The concentration of GPC was highest in the caput and corpus regions of the epididymis, that of phosphocholine changed little along the length of the rat epididymis and there was approximately a 3-fold increase of concentration of inorganic phosphate in the luminal fluid from caput epididymidis to ductus deferens. The estimated total phosphate appeared to equal that of the sum of the phosphate derived from the above compounds. The concentrations of these compounds in the luminal fluid of the testis and in blood plasma were very low.
Animals↗
Effects of passive immunization against testosterone on serum and pituitary gonadotrophins: implications for the relative importance of androgens and inhibin in the control of gonadotrophin secretion in the male rat.
The acute effects of a specific reduction in androgen feedback to the hypothalamus and pituitary gland have been investigated in male rats by passive immunization against testosterone. An ovine antiserum raised against testosterone which had been conjugated through position 3 to bovine serum albumin was employed. Negative feedback control by androgens was effectively reduced by administration of the antiserum, as shown by an increase in levels of LH in the circulation. Immunized animals had a high concentration of testosterone in the circulation of which virtually all was tightly bound to antibody. In normal animals specific increases of serum LH concentration were obtained at all ages using a low dose of antiserum. At higher doses, serum FSH concentration was also increased. The LH response was reduced by anaesthesia and sham-operation. In sham-operated rats given a high dose of antiserum for 3 days the serum concentrations of LH and FSH could not be distinguished from those which followed castration while differences were found in the pituitary contents. It was concluded that testicular androgen provides an important inhibitory feedback control of secretion of FSH as well as that of LH in the adult male rat. Some of the data can best be explained by the action of inhibin as a minor or alternative inhibitor of FSH secretion.
Aging↗
Responsiveness of the pituitary gland to androgens and of the tests to gonadotrophins following damage to spermatogenesis in rats.
To test the interaction of androgen and inhibit feedback on the pituitary gland, inhibin-type feedback from the testes was reduced when they were made aspermatogenetic by bilateral ligation of the efferent ducts or local heating (43 degrees C for 30 min). There were only minor effects on the subsequent response of the pituitary gland to the removal of androgen feedback by the administration of antiserum against testosterone or by castration. However, in the antiserum-injected animals the steroidogenic response of the testis to the increased serum concentrations of LH was less in aspermatogenic than in control rats. Furthermore, unilateral aspermatogenesis was associated with reduced testosterone output by the treated testis and with compensatory increased output by the contralateral control testis, despite the absence of significant changes in serum LH and normal peripheral levels of testosterone. This suggests that the tubules can regulate the responsiveness of the Leydig cells to LH.
Animals↗