). Physiological or psychological stressors that induce the sympathetic nervous system’s ‘fight-or-flight’ response can rapidly increase the norepinephrine (NE) level ( Tank & Lee Wong 2015 ). However, the effect of NE on reproductive toxicity in early pregnancy
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Jiju Wang, Yunhui Tang, Songcun Wang, Liyuan Cui, Dajin Li, and Meirong Du
Giuseppina Mattace Raso, Giuseppe Bianco, Anna Iacono, Emanuela Esposito, Giuseppina Autore, Maria Carmela Ferrante, Antonio Calignano, and Rosaria Meli
Introduction During pregnancy, several neuroendocrine changes and energy metabolism alterations occur. In this hypermetabolic state, a great increase in maternal body fat and weight and a positive energy balance are well recognized
Tracy Josephs, Hayley Waugh, Ilona Kokay, David Grattan, and Mary Thompson
Introduction Pregnancy and lactation are physiological situations where major changes in energy homeostasis occur to meet the nutrient demands of fetal growth and milk production. The energy needs are met by increased food intake
Renée F Johnson, Carolyn M Mitchell, Warwick B Giles, Andrew Bisits, and Tamas Zakar
Introduction Prostaglandins (PGs) produced by intrauterine tissues play important roles throughout gestation. In early human pregnancy, PGs are involved in implantation, pregnancy recognition and the immune tolerance of the fetus
Caiping Mao, Rong Liu, Le Bo, Ningjing Chen, Shigang Li, Shuixiu Xia, Jie Chen, Dawei Li, Lubo Zhang, and Zhice Xu
as renal injury in adults ( Barker 1992 , Boero et al . 2002 , du Cailar et al . 2002 , Logan 2006 ). There has been a fairly large body of research on the impacts of salt exposure in pregnancy ( Coelho et al . 2006 , Digby et al . 2010
Kathryn L Gatford, Miles J De Blasio, Claire T Roberts, Mark B Nottle, Karen L Kind, William H E J van Wettere, Robert J Smits, and Julie A Owens
Introduction Primiparity and adolescent pregnancies each restrict fetal growth in humans and other species, including pigs ( Ritter et al . 1984 , Rasmussen & Fischbeck 1987 , Bryan & Hindmarsh 2006 ). These may both contribute to the reduced
Manish V Sheth, Connie J Mark, and Kathleen M Eyster
the ovaries from days 7 to 20 of pregnancy in the rat when the PKC activity was measured in a way that prevented interference by protein phosphatases ( Eyster et al . 1993 ). In contrast, protein phosphatase activity declined between days 7 and 10 of
J. P. Monson and D. J. Williams
The alterations in water homeostasis which accompany human pregnancy provide a unique example of resetting of osmolar control. The changes have inherent interest as a physiological adaptive mechanism, but do they have pathological significance for patients with previously unrecognized disturbance of water balance? In this commentary we highlight briefly the physiological changes in osmoregulation which occur in pregnancy. The possible mechanisms for these changes, including alterations in the metabolism and action of arginine vasopressin (AVP), are described and we attempt to relate these to the rare, but well recognized, phenomenon of exacerbation of subclinical diabetes insipidus in pregnancy. The tentative associations between AVP metabolism, pre-eclampsia and diabetes insipidus are also addressed.
Physiological water retention of pregnancy
Normal pregnancy is characterized by an early decrease in serum osmolality of up to 10 mosmol/kg which continues throughout gestation (Davison, Valloton & Lindheimer, 1981). This hypotonicity is maintained by a decreased osmotic threshold
T Clark Brelje, Nicholas V Bhagroo, Laurence E Stout, and Robert L Sorenson
Introduction During pregnancy, there is an increased need for insulin to accommodate the developing insulin resistance and growing fetal compartment. The pancreatic islets of Langerhans meet this demand by increasing both insulin secretion and islet
A. D. T. GOVAN
SUMMARY
A histological and histochemical study has been made of ovaries obtained from patients in early pregnancy, the duration of pregnancy varying from 6 to 20 weeks. During the first 10 weeks of pregnancy ovarian structure is virtually unchanged, compared with the post-ovulatory state. From 10 weeks onwards new Graafian follicles appear. These are limited in size, most achieving a maximum diameter of 4 mm. They are characterized by an early and excessive thecal development. Atresia overtakes these follicles and this occurs at all stages of development, suggesting a sudden and possibly recurrent change in gonadotrophic stimulation. Despite atresia the theca persists but histochemical tests suggest that its functional activity is limited. This loss of activity is associated with a recognizable histological change in the thecal cell. It is suggested that most of the alterations in ovarian structure are due to changes in the quality and quantity of gonadotrophins produced at this period of pregnancy.
