Effects of glycyrrhizae and glycyrrhizic acid on cellular immunocompetence in low-dose gamma-ray irradiated mice.

BACKGROUND: For both animals and human beings, it is important to prevent damage from ionizing radiation and to restore immunocompetence following irradiation. The present study was conducted to investigate the effects of glycyrrhizae (GL) and glycyrrhetinic acid (GA) on cellular immunocompetence in low dose gamma-ray-irradiated mice. METHODS: Six- to 8-week-old ICR strain' Crl:CD-1-ICR (BR) strain male mice, bred in the Institute of Cancer Research, U.S.A., were chosen and divided into four groups. Group A was the normal control. Group B, the experimental control, received 1 Gy of whole body gamma-ray irradiation. Groups C and D, the experimental groups, were treated with 500 mg/kg of GL (orally) and 5 mg/kg body weight of GA (i.p.), respectively, once a day, 5 days a week for 2 weeks after gamma-irradiation. The tested mice were killed, at 6 different intervals to measure their leukocyte and differential counts. Cellular immunocompetence was measured by the 3H-thymidine uptake in each group. RESULTS: One gray of gamma-ray irradiation had evident inhibition on the leukocyte and differential counts and the cellular immunity of mice. GL and GA could help to restore the decreased leukocyte counts and the cellular immunocompetence in low dose gamma-irradiated mice. CONCLUSION: GL and GA could help to restore decreased leukocyte counts and the cellular immunocompetence in low-dose gamma-ray-irradiated mice.

Retinoid and androgen regulation of cell growth, epidermal growth factor and retinoic acid receptors in normal and carcinoma rat prostate cells.

Recent in vivo and in vitro studies suggest that retinoic acid receptor (RAR)-mediated processes may be involved in androgen regulation of prostate cells in a manner that may be altered during prostatic carcinogenesis. We tested this hypothesis in the newly established carcinoma and non-carcinoma rat prostate epithelial cell lines, NRP-154 and NRP-152, respectively. In DMEM/F-12 medium supplemented with 10% charcoal stripped fetal calf serum (cFCS), the number of both NRP-152 and NRP-154 cells were stimulated by testosterone (T), with a 4-fold greater effect in NRP-152 than in NRP-154 cells. Retinoic acid (RA) alone also stimulated the growth of NRP-152 cells, but failed to induce cell growth of NRP-154 cells. Importantly, the level of RAR alpha mRNA was elevated whereas the levels of RAR gamma and androgen receptor (AR) mRNA were lower in NRP-154 cells compared to those in NRP-152 cells. Treatment of NRP-152 cells with increasing doses of T resulted in a dose-dependent decrease and rebound of the level of RAR alpha and gamma mRNA in NRP-152 cells; these effects were not apparent, if not reversed, in NRP-154 cells. Both ligand binding and Western blot analyses revealed that epidermal growth factor receptor (EGF-R) was stimulated by 20 nM T but was suppressed by 0.1 microM RA, which also attenuated the stimulating effects of T on EGF-R in NRP-152 and to a lesser extent in NRP-154 cells. The differences in the level and androgen regulation of RAR mRNAs and reciprocal regulation of EGF-R expression by T and RA between NRP-154 and NRP-152 cells suggest that variations in the EGF-R and RAR signal events may contribute to differences in growth rate between these two cell lines.

The detrimental effects of spinal cord injury on spermatogenesis in the rat is partially reversed by testosterone, but enhanced by follicle-stimulating hormone.

Our previous studies have demonstrated that impaired spermatogenesis during the acute phase of spinal cord injury (SCI) is preceded by a transient (but significant) suppression of serum FSH, LH, and testosterone (T) concentrations. It is hypothesized that hormonal deprivation may impair Sertoli cell function, leading to the loss of spermatogonia, degeneration of spermatogenic cells, and eventual regression of the seminiferous epithelium. The current study examined the efficacy of exogenous T and FSH in the maintenance of spermatogenesis and Sertoli cell functions in SCI rats. Implantation of T capsules (TC, 2 x 5 cm) attenuated some of the spermatogenic lesions and maintained qualitatively complete spermatogenesis in all SCI rats 4 weeks after the surgery. In contrast, daily injections of 0.1 U of FSH alone, or in combination with TC implants, paradoxically enhanced the regression of spermatogenesis in SCI rats. At this time, the numbers of Aal, A1, and B spermatogonia and preleptotene spermatocytes in SCI rats have decreased by 25-30%. Though not prevented by TC implants, the decrease in Aal and A1 spermatogonia was attenuated by FSH alone but was further enhanced when FSH-treated rats also received TC implants. The intratesticular T concentration in untreated and FSH-treated SCI rats was not different from that of sham control rats, but it decreased by more than 95% in those SCI rats given TC implants alone. These results demonstrate that impairment of spermatogenesis during the acute phase of SCI is not related to the availability of FSH and/or T. Northern blot analysis revealed an increase in androgen receptor messenger RNA (mRNA) in the testis of SCI rats; this increase was prevented by TC implants but persisted when FSH was also given. In contrast, the levels of FSH-receptor, androgen binding protein, and transferrin mRNA were not affected by SCI but were significantly higher in those SCI rats given FSH alone or in combination with TC. TC implants alone suppressed mRNA levels of transferrin in testes of SCI rats, without concomitant change in those for FSH-receptor and ABP. The changes in Sertoli cell responses to FSH and T, and perhaps other hormones, may alter signal events elicited by these hormones, thus contributing to abnormal epithelial environments and regression of spermatogenesis. Maintenance of spermatogenesis in SCI rats by exogenous T suggests the feasibility of using exogenous hormones to impede the detrimental effects of SCI on spermatogenesis. This approach may have clinical applicability for the preservation of spermatogenic functions in SCI men.

The use of Chinese herbal medicine on experimental fracture healing.

The purpose of this study was to examine the effect of Ru-Yih-Jin-Huang-Saan (RYJHS) and Jie-Guu-Saan (JGS) on experimental fracture healing in rats. Seventy-five rats were fractured in the middle of the left tibia and fibula. They were randomly divided into experimental and control groups and injected with Ringer's solution and applied with Ru-Yih-jin-Huang-Saan externally or fed with Jie-Guu-Saan respectively. The animals were sacrificed at 4, 8 and 12 days after fracture. The contents of hydroxyproline and the synthesis of DNA, RNA and protein were observed. The results demonstrate that groups treated with herbal medicine were more rapidly and thoroughly healed than the control group in respect to collagen formation and bone cell metabolism.

Induction of enrichment of the stages of the seminiferous epithelial cycle in prepubertal rats.

The aim of the present study was to examine the feasibility of inducing enrichment of the stages of the seminiferous epithelium in prepubertal male rats produced by vitamin A-deficient (VAD) females that had received a supplement of a marginal level of retinol. Seventy-day-old retinoic acid-supplemented VAD female rats were given daily doses of 5, 10, or 20 micrograms retinol for 2 wk. Breeding of these females resulted in the production of viable offspring in litters of normal size. Subsequently, male rats so produced (VAD males) were given a single injection of 10 or 20 micrograms retinol at 10 or 20 days of age, fostered by normal lactating females, and weaned at 25 days of age. These rats were maintained on normal rat chow thereafter. At 10 days of age, active spermatogonial proliferation was not seen in the testes of VAD males born to VAD females receiving a 5- or 10-micrograms daily dose of retinol. Concurrently, cells resembling gonocytes were frequently seen, and pre-type A spermatogonia were seen in over 80% of the tubules examined. By 20 days of age, the presence of active spermatogonial proliferation was demonstrated by the appearance of preleptotene spermatocytes, but these failed to differentiate further. Spermatogenesis of the VAD males born to VAD females given a daily dose of 20 micrograms retinol appeared to be normal at both 10 and 20 days of age. Forty days after the retinol replacement, the testes of VAD males born to VAD females given a daily dose of 5 or 10 micrograms retinol were enriched with specific stages of the seminiferous epithelium while other stages were absent. The stages enriched were affected by the dose of retinol administered and the age when retinol replacement began. The stage enrichment in these animals persisted for at least 135 days. Seminiferous epithelium of the VAD males born to the VAD females receiving a 20-micrograms daily dose of retinol was not stage-enriched. Northern blot analysis of testicular RNA revealed stage-dependent changes in the steady-state level of mRNA for spermatid protamine and Sertoli cell androgen-binding protein (ABP). Results of this study demonstrate the feasibility of inducing enrichment of seminiferous stages in prepubertal rats. The production of this animal model is cost-effective in that it saves in time and animal maintenance.(ABSTRACT TRUNCATED AT 400 WORDS)

[Effects of gossypol acetate, danazol, progesterone and GnRH-A on estrogen and progesterone receptors of human endometrial cells].

In order to evaluate the drugs in treating endometriosis, the direct effects of gossypol acetate, danazol, progesterone, and gonadotropin releasing hormone-agonist (GnRH-A) on the isolated human endometrial cells were determined by DCC assay. The binding capacity of cytosolic estradiol receptor (E2R) and progesterone receptor (PR) in groups treated with gossypol acetate or progesterone decreased. In danazol-treated group, the binding capacity of PR decreased but not that of E2R. GnRH-A showed no significant effect on the binding capacity of E2R and PR. There was a significant linear correlation between the inhibitory rates of PR binding capacity of progesterone and danazol. The results suggested that gossypol acetate, danazol and progesterone might have peripheral effects mediated by steroid receptors, while GnRH-A work clinically through the central path way only.

Combined effects of chuling (Polyporus umbellatus) extract and mitomycin C on experimental liver cancer.

Chuling (Polyporus umbellatus), one of the commonly used Chinese medical herbs, was combined with mitomycin C and then studied against intrahepatic implantation of sarcoma 180 tumor cells in mice. Oral administration of chuling extract, intraperitoneal injection of mitomycin C and the combination of both increased the life span of tumor-bearing mice 71.6%, 70.1% and 119.9%, respectively. The same treatments were found to be cytotoxic to Sarcoma-180-induced liver tumor cells. The synthetic rates of DNA, RNA and protein were all inhibited measurably by the combined treatment. Histopathological studies showed that lymphocytes infiltrated and surrounded the cancer cells, and there was some fibrosis found in normal cells and cancer cells. These results indicate the potential use of chuling as an anticancer agent.

Failure of spermatid release under various vitamin A states - an indication of delayed spermiation.

Vitamin A deficiency (VAD) was induced in male Sprague-Dawley rats by feeding them a vitamin A-deficient diet after weaning and subsequently supplementing their diet with retinoic acid. The serum vitamin A levels of these rats were at a minimum by 60 days of age. Although spermatogenesis can proceed normally during the early phase of vitamin A deficiency, a small number of late spermatids were not released from the seminiferous epithelium at the end of Stage VIII of the cycle of the seminiferous epithelium but rather at a later stage. This observation suggests a delay in spermiation. This delayed spermiation was noted as early as 50 days of age and persisted in rats even after 60 days of vitamin A replacement. These results demonstrate that in rats the timing of spermiation can be retarded by vitamin A deficiency. Although the mechanisms causing this delay in spermiation are not known, the vitamin A-deficient rat provides a useful model system for studies on the regulation of spermiation.