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Biomedical subjects

E Kawakami

Publications and source records attributed to E Kawakami.

At least 19 recordsLinked to original sources
PubMed1995

Short-term oral treatment of canine benign prostatic hypertrophy with chlormadinone acetate.

Ten beagle dogs (4-8 years of age) with benign prostatic hypertrophy were treated daily for 7 or 14 days by a daily oral administration of chlormadinone acetate (CMA), an anti-androgenic preparation, at a dose of 0.5 or 2.0 mg/kg/day. The groups of dogs treated with CMA at a dose of 2.0 mg/kg showed a greater reduction of the prostatic volume during 7 or 14 days of treatment than the group treated with 0.5 mg/kg of CMA. At 56 and 84 days after the start of CMA treatment, prostate volume was reduced to 63 and 79% of the pre-administration volume, respectively. No marked decrease in plasma LH or testosterone was found after the CMA treatment. These results indicate that the therapeutic effects of 7-day oral treatment with CMA at 2.0 mg/kg/day in dogs with BPH last for about three months or longer without side effects.

Administration, Oral↗
PubMed1995

Effect of chlormadinone acetate-pellet implantation on the volume of prostate, peripheral blood levels of sex hormones and semen quality in the dog.

Chlormadinone acetate (GS implant, CMA) pellet, a synthetic luteal hormone preparation, was subcutaneously implanted at 5, 10 and 20 mg/kg in four normal male dogs ranging in age from 3 to 10 years to determine the changes in the prostatic volume, peripheral plasma levels of sex hormones and semen quality. The plasma levels of CMA, LH, testosterone (T) and 5 alpha-dihydrotestosterone (DHT) were measured by radioimmunoassay. The prostatic volume was measured by computed tomography. The semen was collected by digital manipulation. The pellet was removed 26 weeks after implantation. The effects of CMA pellet implantation were examined during implantation and until 22 weeks after removal. The prostatic volume was reduced to 61 +/- 3 (mean +/- S.E., n = 4), 52 +/- 5 (n = 4) and 53 +/- 9 (n = 4)% of the preimplantation volumes in the 5, 10 and 20 mg/kg groups, respectively. The plasma CMA levels in the 10 mg/kg and 20 mg/kg groups peaked at 2 weeks, but were gradually decreased. At 22 weeks after removal of the pellet, the prostatic volume returned to 74-85% of the preimplantation volumes. The plasma LH levels tended to increase after implantation in all groups. The plasma T and DHT levels were slightly decreased in all groups. In the 10 and 20 mg/kg groups, the number of sperm and motility sperm was reduced, and the rate of abnormal sperm increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1991

Effects of LHRH-analogue treatment of spermatogenic dysfunction in the dog.

Three male dogs, aged 2-4 years, which exhibited a high percentage of sperm with abnormal tails in their semen and low levels of peripheral plasma LH and testosterone were given two injections of 400 micrograms an LHRH analogue (LHRH-A) 3 h apart. The semen quality of all three dogs and the peripheral plasma levels of LH and testosterone were examined in two of the dogs. Plasma levels of LH and testosterone in both dogs peaked at 30 and 90 min respectively, after the injection of LHRH-A. The semen quality of all three dogs had improved temporarily 20 days after the injection. To be specific, although the mean percentage of sperm with abnormal tails in the three dogs was 19, 26 and 32% respectively before injection of LHRH-A, these values had decreased to 10, 16 and 13%, respectively, 20-40 days later. Thereafter, however, the percentage sperm abnormalities increased again. The testes and epididymides of two of the dogs were examined histologically at the end of 90 days. Sloughed germ cells were observed in the seminiferous tubules of the testes, and pyknotic epithelial cells were noted in some of the epididymal ducts. The other dog, which had a history of three unsuccessful matings was treated again with LHRH-A and mated with three bitches 30, 75, and 110 days later, respectively. Only the bitch mated with this dog 30 days after a second series of injections conceived. It is assumed that the semen quality of the three dogs improved because of a temporary rise in plasma LH and testosterone levels after the injection of LHRH-A. It is concluded that the fertility of dogs with a high percentage of sperm with abnormal tails can be improved approximately 30 days after treatment with an LHRH-A.

Animals↗
PubMed1991

Response of the lactating and postweaning sow to gonadotropin releasing hormone (GnRH).

Clinical and endocrinological responses to administration of gonadotropin releasing hormone analog (LH-RH-A) during the lactation period and postweaning in the sow were investigated. Plasma LH concentrations in lactating sows rose immediately after administration of LH-RH-A. However, in postweaning sows the increase of LH level was more slowly. Three of 5 postweaning sows came into estrus and ovulated after LH-RH-A treatment. One sow exhibited a distinct LH response, but her ovaries remained quiescent. The remaining one with feeble estrus for a short period became cystic ovaries. Thus, LH response to GnRH in the sow seems to be higher during early lactation than at 2 days postweaning.

Animals↗
PubMed1991

Histological observations of the reproductive organs of the male dog from birth to sexual maturity.

Development of the testis, epididymis and prostate in 53 male beagles was examined histologically with PAS-hematoxylin stain from birth to sexual maturity. The diameter of the seminiferous tubules of the testes was less than 100 microns until 20 weeks of age, however, it increased markedly between 22 and 28 week of age, reaching 180 +/- 7 (mean +/- SD) microns at 28 weeks of age. Only Sertoli cells and gonocytes (or spermatogonia) were detected in the seminiferous tubules until 16 weeks of age. Spermatocytes and spermatids appeared in the tubules at 20 and 22 weeks of age, respectively. Spermatozoa were first observed in the testes of 2 of the 5 dogs at 26 weeks of age and were found in the testes of all the 3 dogs at 28 weeks of age. The diameter of the ducts in the cauda epididymidis was 146 +/- 4 microns at 20 weeks of age. Thereafter it increased markedly, reaching 341 +/- 14 microns at 28 weeks of age. The height of the epithelium and stereocilia in the ducts of the caput epididymidis increased markedly at about 28 weeks of age. A large number of spermatozoa was seen in the lumens of the ducts of the corpus and cauda epididymidis after 32 weeks of age. The shape of the lumens in the glandular alveoli of the prostate became irregular as a result of projection of the glandular epithelium into the enlarged lumens and the epithelial cells of the alveoli became PAS-positive at 24 weeks of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Hyperactivation and acrosome reaction in vitro in spermatozoa ejaculated by cryptorchid dogs after orchiopexy.

Orchiopexy of the cryptorchid (CR) testis and castration of the scrotal testis were performed in three unilaterally CR beagles at six months of age. Induction rates for ejaculated sperm hyperactivation (HA) and the acrosome reaction (AR) in vitro in these orchiopexied dogs were compared with five those in normal beagles one year later. Canine spermatozoa were incubated for 9 hr at 38 degrees C under 5% CO2 in air in canine capacitation medium at a concentration of 30 x 10(6) sperm/ml. HA was observed using high-speed videomicrography. The AR spermatozoa were evaluated by the triple stain technique. As a result, there was no significant difference between 'the CR dogs after orchiopexy' (CDO) and the normal dogs (ND) with respect to sperm motility just after ejaculation. However, sperm motility of CDO decreased markedly during incubation. There was a significant difference in sperm motility between CDO (Mean +/- SD; 47 +/- 12%) and ND (80 +/- 9%) after three hours of incubation (p less than 0.01). No significant difference was observed between CDO and ND with respect to the HA rate of motile spermatozoa throughout the incubation period. The peak of HA rate was found in both CDO (58 +/- 5%) and ND (61 +/- 16%) after seven hours of incubation. The AR rate of spermatozoa in CDO was lower than that in ND after six hours of incubation. The AR rate of CDO (26 +/- 4%) was significantly lower than ND (46 +/- 5%) after eight hours of incubation (p less than 0.01). It is assumed that there might be relation between a rapid decrease of motility and low AR rate in spermatozoa of CDO during incubation.

Acrosome↗
PubMed1990

Androgen concentration in the blood and spermatogenic function of tom cats during the breeding season.

In order to better understand androgen secretion in the tom cat during the breeding season, observations of diurnal changes in peripheral blood testosterone (T) levels, were made and the relation between androgen levels (androstenedione (A), 5 alpha-dihydrotestosterone (DHT). T) in testicular and peripheral vein blood was borne. Histologic examinations of the testis were also performed to investigate spermatogenic function. The 9 tom cats used in these studies were 2-3 years old, weighed 3.5-4.0 kg, and were raised in a room under natural lighting. As a result, diurnal peripheral blood T levels in the tom cat fluctuated greatly according to each individual, but since no definite trend could be identified, secretion was determined to be episodic. Although fairly large differences in the 3 types of androgen were observed in testicular vein blood depending on the individual animal, levels on the left and right were almost equal. Moreover, a correlation was found between the testicular and peripheral vein blood concentrations of the 3 androgens (A: p less than 0.01; DHT: p less than 0.05; T: p less than 0.01). Therefore, secretion of testicular androgen can be inferred by measuring peripheral blood androgen levels. Testicular histological examination revealed active spermatogenesis in all of the cats, and no significant inter individual differences were detected in either seminiferous tubule diameters or any of the various germ cells.

Androstenedione↗
PubMed1989

Effects of prostaglandin F2 alpha-analogue administration on luteal function, implantation of embryos and maintenance of pregnancy in bitches.

The present experiment was carried out to clarify the effect of administration of the prostaglandin F2 alpha (PGF2 alpha)-analogue on the luteal function and the maintenance of pregnancy in bitches. Fifty-one bitches received a single inoculation of PGF2 alpha-analogue by intramuscular injection. The effect of this agent was observed by monitoring progesterone (P) levels and the state of the uterus by laparotomy, the occurrence of abortion, and the state of parturition. As a result, when bitches were administered with 100-400 micrograms at the beginning of the luteal phase, the decrease in the P level was temporary. In bitches inoculated with 100-800 micrograms of PGF2 alpha-analogue at the functional luteal stage, the P level began to decrease as early as on the following day after injection. In those treated with 100-200 micrograms of PGF2 alpha-analogue at 10-15 days of pregnancy, pregnancy was maintained in 3 of 5 bitches that had received the treatment at day 10, while in the remaining two, all embryos died after implantation. In those that had received the same treatment at day 15, only 2 of 7 maintained pregnancy. Pregnancy was interrupted in eight bitches treated with doses of 100-200 micrograms at days 25-45. In four bitches treated with doses of 100-200 micrograms at day 55, premature birth was induced after 30-44 hr. In conclusion, regression of the corpus luteum, abortion, and premature birth were induced in bitches treated with 100-200 micrograms at each stage, except the beginning of the luteal phase and of the pregnancy.

Animals↗
PubMed1989

Transport of spermatozoa in the reproductive tract of the bitch: observations through uterine fistula.

Using unilateral uterine fistulas, the time required for spermatozoa to reach the end of the fistula after natural mating, artificial insemination (AI) in a normal standing posture (NP), and AI standing on the head (SH) was investigated in each of three stages of estrus. Conceptivity in these bitches was also investigated. Five experimental bitches were tested during a total of 8 estrous periods. The results are as follows; the time required for spermatozoa to reach the end of the fistula was almost the same in the early and middle stages, i.e., 30 sec to 1 min after natural mating and SH and less than 2 min for half the bitches in NP, although no intrauterine transport could be observed in the other half. In most cases of mating during the late stage no spermatozoa were found after any of the 3 methods of insemination. Five animals became pregnant in these experiments, but the other three failed to conceive. The implantation of fertilized ova occurred also in the fistulated uterine horn in all cases of pregnancy.

Animals↗