title: Relationship between human chorionic gonadotrophin-induced changes in testicular microcirculation and the formation of testicular interstitial fluid.
abstract: The relationship between testicular vascular permeability and testicular microcirculation as measured by laser Doppler flowmetry was studied in adult rats. In untreated control animals there was an oscillatory testicular blood-flow pattern with a frequency of 10.6 +/- 0.8 pulses/min and the amount of testicular interstitial fluid (IF) collected was 61.5 +/- 2.2 microliter/g testis. Treatment of the rats with 25-200 i.u. human chorionic gonadotrophin (hCG) s.c. 8 h before the experiment resulted in a change in the testicular flow pattern from pulsatile to continuous and an increase in IF volume. Treatment with hCG (50 i.u., s.c.) changed the testicular blood-flow pattern from oscillatory to continuous 4, 8 and 16 h after treatment. The flow pattern returned to being pulsatile 32 h after treatment with hCG. The IF information was increased at those times when the blood-flow pattern was continuous. No effects on blood flow or IF formation were observed with 12.5 i.u. hCG s.c. The present study shows a dose- and time-dependent covariation between the increase in testicular IF volume and the disappearance of the pulsatile flow in testicular microcirculation. It appears that a continuous flow pattern favours the transport of fluid from blood vessels to the interstitium.
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D002199:Capillary Permeability; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005110:Extracellular Space / Q000502:physiology*; D007834:Lasers; D008297:Male; D008833:Microcirculation; D051381:Rats; D011919:Rats, Inbred Strains; D013737:Testis / Q000098:blood supply* / Q000187:drug effects; D013997:Time Factors
chemical_list: D006063:Chorionic Gonadotropin