title: A novel stereotaxic approach to the hypothalamus for the use of push-pull perfusion cannula in Holstein calves.
abstract: To determine secretory patterns of growth hormone-releasing hormone (GHRH) and somatostatin (SS) and their roles in the regulation of growth hormone (GH) secretion, a method for collecting hypothalamic perfusates, a push-pull perfusion method was developed in calves. With the use of the stereotaxic apparatus for cattle, a cannula was implanted into the hypothalamus of four male calves based upon cerebral ventriculography. Push-pull perfusates were collected at 10 min intervals for 6h and GHRH and SS concentrations in perfusates and plasma GH concentration were determined by EIAs and RIA, respectively. A cannula was implanted into the hypothalamus based on the image of the third ventricle and maintained for 1 month. GHRH and SS showed pulsatile secretion and the pulses for GHRH and SS were irregular in conscious animals. Neither GHRH nor SS secretion had a clear relationship with GH secretion. In the present study, we thus (1) established a stereotaxic technique for approaching the hypothalamus using cerebral ventriculography for calves, and (2) demonstrated that GHRH and SS secretion were pulsatile but not closely related to GH profile in conscious calves. The technique is useful for the study of the functions of the hypothalamus in the control of pituitary hormones in cattle.
authors.affiliation: Physiology and Genetic Regulation Department, National Institute of Agrobiological Sciences, 2 Ikenodai, Tsukuba 305-0901, Japan. etsukok@affrc.go.jp
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kasuya
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Sakumoto
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Saito
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Hideo
authors.initials: H
authors.lastname: Sengoku
authors.forename: Tetsu
authors.initials: T
authors.lastname: Nemoto
authors.forename: Koichi
authors.initials: K
authors.lastname: Hodate
mesh_terms: D000818:Animals; D002404:Catheterization / Q000295:instrumentation* / Q000379:methods*; D002417:Cattle; D013007:Growth Hormone-Releasing Hormone / Q000032:analysis / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism; D007031:Hypothalamus / Q000033:anatomy & histology / Q000378:metabolism / Q000601:surgery*; D015918:Infusion Pumps, Implantable; D008297:Male; D008473:Median Eminence / Q000033:anatomy & histology / Q000378:metabolism / Q000601:surgery; D010477:Perfusion / Q000295:instrumentation* / Q000379:methods*; D010507:Periodicity; D013004:Somatostatin / Q000032:analysis; D013238:Stereotaxic Techniques / Q000295:instrumentation*; D020542:Third Ventricle / Q000033:anatomy & histology / Q000601:surgery
chemical_list: D013004:Somatostatin; D013007:Growth Hormone-Releasing Hormone