The effect of hypothyroidism on the female genital tract of gerbils (Meriones hurrianae jerdon).

The effects of hypothyroidism on the female genital tract of gerbils have been studied. Hypothyroidism was produced by (a) surgical ablation, and (b) pharmacological suppression of the gland. Hypothyroidism resulted in atrophic ovaries. Follivular development was severely arrested, with most of the follicles showing atresia. Distinct effects were produced upon the uterine physiology. Uterine regression was conspicuous in thyroidectomized females. Hypothyroidism resulted in a decreased RNA, protein, sialic acid and glycogen concentration of the uterus. Vaginal RNA, protein and sialic acid contents were low after thyroidectomy. The vaginal cytology showed a constant pattern of its cells, i.e. dioestrous. L-thyroxine treatment restores the biochemical changes of uterus and vagina to subnormal levels in thyroidectomized animals. It is concluded that hypothyroidism affected the weight, cytology and biochemistry of the female genital tract of gerbils.     

Long-term effect of vasectomy on the biochemical composition of testes and sex accessory organs of the Indian desert gerbil, Meriones hurrianae Jerdon.

A long-term vasoligation operation in gerbils, Meriones hurrianae Jerdon did not reveal any consistent change in the weights of androgen dependent organs such as seminal vesicles, ventral prostate, epididymes and perineal complex (levator ani muscle and penis). Histological structure of the testis and caput epididymis remains normal after vasectomy. There was no effect of bilateral vasectomy on androgen production of the testes as reflected by fructose content of coagulating gland. No compensatory hypertrophy of the contralateral testis was observed in unilaterally vasectomized gerbils. The RNA content of the testis and epididymis and ascorbic acid content of adrenal gland did not show appreciable change. No change in protein content of the testis was found but a significant increase was observed in the protein content of epididymis after the operation.     

Histochemical demonstration of certain testicular enzymes of the Indian desert gerbil Meriones hurrianae jerdon and their response to unilateral cryptorchidism

Summary Active male gerbils were rendered unilaterally cryptorchid and the enzymatic changes were studied after 48, 60 and 100 days. The histochemical observations revealed inhibition of alkaline phosphatase, acid phosphatase, 5-nucleotidase, adenosine-tri-phosphatase and succinic dehydrogenase activities in the germinal elements of the seminiferous tubules. The non-specific esterase and succinic dehydrogenase activities increased in the Leydig cells to certain extent. The sudanophilic lipids increased in the Sertoli cells and the interstitial cells. An attempt has been made to approach the intricate problem of the spermatogenesis in order to understand the sequence of certain enzymatic activities in the gerbil testis in which spermatogenesis is suppressed when one of the testes is lodged inside the abdominal cavity.     

Impact of aggressive encounters on reproductive behaviour in the Indian desert gerbil,Meriones hurrianae (Jerdon)

The gerbils were exposed to daily I min aggressive encounters for 30 days, to study the effect of social stress on reproduction. The encounters were induced by introduction of an adult male or female gerbil into the cage of a male retired breeder living in isolation. In the male gerbils the encounters decreased (P < 0.001) gonadal weight and sperm counts. The accessory sex organs responded variedly to the encounters. The surface areas of abdominal scent glands decreased (P < 0.001). The results suggest that exposure to aggressive encounters had a negative influence on male reproduction in the gerbil. Contrary to the results in male gerbils, encounters with males had a positive influence on reproduction in females. This was evidenced by data on ovarian and uterine weights, follicular kinetics and the estrous cycle. The ovarian and uterine weights increased (P < 0.001) in gerbils exposed to the encounters. The number of estruses increased (P < 0.001) whereas the diestruses decreased. Study of follicular kinetics revealed an increase in the number of growing follicles and a decrease in the number of regressive follicles. The mechanism(s) by which the encounters influence reproduction is not known. Adrenal gland weights increased (P < 0.001) in both male and female gerbils exposed to the encounters. The pinealocyte cell and nuclear diameters decreased (P < 0.01) in males and increased (P < 0.001) in female gerbils after the encounters. Presumably the adrenal and pineal glands may play an important role mediating the effects of the encounters.     

Effects of Malva viscus conzattii Greenm flower extract on testicular function of the house rat Rattus rattus Rufescens & the gerbil Meriones hurrianae Jerdon: a biochemical study

Extract of the flower Malva viscus conzattii (M. conzattii) was administered at a dose of 25/50 mg/day/animal to 30 healthy adult male gerbils and 30 adult male house rats to determine its effect on fertility. After 25 days' treatment fin l body weight, and the weights of testes, epididymides, seminal vesicles, and adrenal glands were measured. Testis, epididymides, and seminal vesicles were prepared for histological examination and total protein, RNA, sialic acid, and alkaline phosphatase activity were determined. Quantitative estimation of cholesterol was also made. While overall body weight remained stable during treatment, testicular weight in both animals was drastically decreased. A complete spermatogenic arrest in the testes was evident in house rats treated with 50 mg/day for 20 days and in the gerbil treated with 25 mg/day for 25 days. The seminiferous tubules showed marked degeneration, lined by 1 or 2 cell layers. Epididymides showed degenerative changes as well. RNA contents of the testes, epididydmides, and seminal vesicles of treated anials were significantly lowered as was sialilc acid content. Total cholesterol was increased significantly. M. conzattii causes an effective inhibition of spermatogenesis in gerbils and house rats in 25 states and induces infertility.     

Effects of methallibure (I.C.I. 33828) on the female reproductive tract of the Indian Desert gerbil (Meriones hurrianae Jerdon).

Effects of methallibure (I.C.I. 33828) have been studied on the reproductive organs of female gerbils, Meriones hurrianae. Methallibure administration caused reduction of gonadal weight indicating suppression of pituitary gonadotrophins. In the ovaries of the treated females extensive atresia of follicles and of corpora lutea was observed. In addition methallibure interrupted the sex cycle, and a dioestrous vaginal pattern was retained throughout medication. A significant decrease in the level of RNA, protein and sialic acid in the uterus and vagina and of glycogen in the uterus was found. Histological and biochemical changes in the ovaries and uteri suggest a possible direct antioestrogenic action of the compound.     

Effects of chemical occlusion of vas deferens on the reproductive organs in gerbil Meriones hurrianae Jerdon.

Male gerbils were sterilized by giving a single injection of a sclerosing chemicial (5% KMnOH) directly into the vasa. After 3 weeks the gerbils were killed. Testes, accessory sex organs, and thyroid and adrenal glands were removed and weighed. Halves of testis and epididymides were fixed in Bouin's fluid fo r microscopic study. The remaining halves were frozen and total RNA, protein, sialic acid, seminal vasicular fructose, and testicular lipids were later determined. Cholesterol estimations were also made. 2 weeks following vas injections animals were tested by exposing them to cycling estrous females. 21 days later the females were examined for possible implantation sites. It was shown that the males had been sterile. Weights of testicles, accessory sex organs, thyroid and adrenal gland remained normal, except that there was a significant increase in the weight of the ventral prostate. No histological changes were found in the testes. Protein content of the testes, epididymides, and seminal vesicles did not change. A decrease in RNA was noted. Sialic acid levels did not alter. Cholesterol and total lipids were normal. Alkaline phosphatase activity in the testes and epididymides had not changed after 3 weeks. Vasicular fructose was normal. Complete occlusion of the vasa resulted. After 100 days there was no return to fertility. The results appear to be permanent.