Author: John Perry PolidoroPublisher:
ISBN:
Category : Ovulation
Languages : en
Pages : 150
Book Description
The Effect of Adrenergic Drugs on Ovum Transport Through the Rabbit Oviduct
Author: John Perry PolidoroPublisher:
ISBN:
Category : Ovulation
Languages : en
Pages : 150
Book Description
Effect of Hormone Pretreatment on Contractility of Rabbit Oviductal Isthmus
Author: Dorianne E. RheaumePublisher:
ISBN:
Category : Oviduct
Languages : en
Pages : 0
Book Description
The exact mechanism for the hormonal modification of ovum transport is not known. The effects of transmural stimulation and of adrenergic agonists on the contractility of isthmic circular muscle of the oviduct were investigated in rabbits in estrus and after hormone treatments which disrupt normal ovum transport. We studied certain oviductal adrenergic mechanisms to define their possible role in mediating hormonal control over oviduct function. Stimulation at 24 Hz was maximal in all tissues but the tension developed was greater in the Estrous group than in the HCG-treated groups. Also, the frequency required to produce a 50% of maximum response was less in Estrous tissues. Cocaine, hydrocortisone and propranolol did not eliminate these differences. Both a- and g-adrenoceptors were present in all tissues. The a-receptors were predominant in all cases; transmural stimulation, adrenaline and noradrenaline always caused contractions that were blocked by phenoxybenzamine. (-)-Adrenaline was more potent than (-)-noradrenaline or (-)-phenylephrine in all tissues. Agonist potency between groups did not vary but for one notable exception: in HCG + Progesterone tissues, noradrenaline was significantly less potent than in the Estrous or HCG + Estrogen groups. Modifications in catecholamine reuptake processes and a- and g-adreno- ceptor sensitivity changes were investigated as possible explanations for these observations. Neither cocaine (3 x 10~^M) nor cocaine + hydrocortisone (10 _/[pipe] M) eliminated the between-group noradrenaline potency differences. a-Adrenoceptor sensitivity did not vary between groups, since the potencies of phenylephrine in the presence of propranolol and of adrenaline in the presence of cocaine + hydrocortisone + propranolol were not affected by hormone treatment. Propranolol (3.8 x 10 _ ^M) potentiated noradrenaline only in the HCG + Progesterone group and abolished between-group noradrenaline potency differences. Therefore, the possibility of increased 3-activity in HCG + Progesterone tissues was further investigated. We studied 3-activity by measuring the ability of adrenergic agonists to inhibit contractile responses to acetylcholine in the presence of cocaine + hydrocortisone + pre-exposure to phenoxybenzamine. (±)-Iso- prenaline inhibited the acetylcholine response by 90% in HCG + Progesterone tissues but by only 30% in Estrous tissues. Papaverine, however, a nonspecific smooth muscle relaxant, produced identical dose-response curves in both hormone groups. ID^q values for (±)-isoprenaline, calculated from normalized curves, were not significantly different, however. The order of agonist potency on 3-adrenoceptors ((±)-isoprenaline > ( )-noradrenaline >(-)-adrenaline ”(±)-salbutamol), as well as pA 2 values for 3-antagonists, propranolol (8.3) and practolol (5.3) were similar to those quoted by Furchgott (1972) for 3i~receptors. These results indicate that HCG + Progesterone-pretreatment causes increased 3-activity possibly by increasing numbers of 3-receptors, and also suggest that the 3-receptor is largely 3j_ in nature. Increased 3-activity may be responsible for the reduced responsiveness to noradrenaline following progesterone treatment; this adrenergic phenomenon might decrease the isthmic barrier to transport and result in accelerated ovum transport.
The Oviduct and its Functions
Author: A.D. JohnsonPublisher: Elsevier
ISBN: 032315266X
Category : Nature
Languages : en
Pages : 390
Book Description
The Oviduct and Its Functions focuses on the role of the oviduct in reproduction. The book emphasizes that this organ combines factors such as environment, hormonal balance, and biochemical constituents to make reproduction possible. Composed of contributions that are divided into 13 chapters, the book presents the comparative anatomy, histology, and morphology of the mammalian oviduct. The selection particularly notes the structural features of this organ. The text proceeds with the discussions on histochemistry and electron microscopy of the bovine oviduct, and then notes that few studies have been reported on this concern. The discussions shift with the presentation of the neural control of the oviduct. Concerns include the presence of alpha and beta receptors in the organ; adrenergic and cholinergic innervation; and the influence of drugs on ovum transport. The text further underscores fluid flow and composition of oviducal fluids in animals. The book points out that the oviduct is vital in the capacitation process and fertilization and responsible for the transport of gametes and survival of sperm. The text also notes that the female reproductive tract is responsible in sperm storage. The book ends with discussions on the influence of genetics, ovulation, and pregnancy on the functions of the oviduct. The compilation is vital for readers interested in studying the functions of the oviduct.
Adrenergic Activators and Inhibitors
Author: Publisher: Springer Science & Business Media
ISBN: 3642675840
Category : Medical
Languages : en
Pages : 953
Book Description
Population Sciences
Author: Cumulated Index Medicus
Author: Dissertation Abstracts International
Author: Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 704
Book Description
Adrenergic Activators and Inhibitors
Author: L. SzekeresPublisher:
ISBN:
Category : Neuropharmacology
Languages : en
Pages : 968
Book Description
Author: 
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