title: Effect of a single injection of gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) on testicular blood flow measured by color doppler ultrasonography in male Shiba goats.
abstract: Although color Doppler ultrasonography has been used to evaluate testicular blood flow in many species, very little has been done in goat. Eight male Shiba goats were exposed to a single intramuscular injection of either gonadotropin-releasing hormone (GnRH group; 1 µg/kg BW) or human chorionic gonadotropin (hCG group; 25 IU/kg BW). Plasma testosterone (T), estradiol (E2) and inhibin (INH) were measured just before (0 hr) and at different intervals post injection by radioimmunoassay. Testis volume (TV) and Doppler indices, such as resistive index (RI) and pulsatility index (PI) of the supratesticular artery, were measured by B-mode and color Doppler ultrasonography, respectively. The results indicated an increase in testicular blood flow in both groups, as RI and PI decreased significantly (P<0.05), but this increase was significant higher and earlier in hCG group (1 hr) than in the GnRH group (2 hr). A high correlation was found for RI and PI with both T (RI, r= -0.862; PI, r= -0.707) and INH in the GnRH group (RI, r=0.661; PI, r=0.701). However, a significant (P<0.05) correlation was found between E2 and both RI (r= -0.610) and PI (r= -0.763) in hCG group. In addition, TV significantly increased and was highly correlated with RI in both groups (GnRH, r= -0.718; hCG, r= -0.779). In conclusion, hCG and GnRH may improve testicular blood flow and TV in Shiba goats.
authors.affiliation: Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, Tokyo183-8509, Japan.
authors.forename: Haney
authors.initials: H
authors.lastname: Samir
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Sasaki
authors.forename: Eman
authors.initials: E
authors.lastname: Ahmed
authors.forename: Aly
authors.initials: A
authors.lastname: Karen
authors.forename: Kentaro
authors.initials: K
authors.lastname: Nagaoka
authors.forename: Mohamed
authors.initials: M
authors.lastname: El Sayed
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Taya
authors.forename: Gen
authors.initials: G
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000662:veterinary*; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000494:pharmacology*; D004958:Estradiol / Q000097:blood / Q000378:metabolism; D006041:Goats / Q000502:physiology*; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D007265:Inhibins / Q000097:blood / Q000378:metabolism; D008297:Male; D013737:Testis / Q000098:blood supply*; D013739:Testosterone / Q000097:blood / Q000378:metabolism; D013997:Time Factors; D018615:Ultrasonography, Doppler, Color / Q000662:veterinary*
chemical_list: D006063:Chorionic Gonadotropin; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D004958:Estradiol; D007265:Inhibins