Influence of altitude and cold on pregnancy and lactation of rats fed on two different diets

Weihe, W. H.

doi:10.1007/bf02187308

Cited by 12 publications

(13 citation statements)

References 10 publications

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“…After exposure to high altitude, regardless of how the values were expressed, the levels of cytochrome P-450 in the adrenal glands were reduced in foetuses of all ages, compared with values obtained from animals kept at sea level. DISCUSSION The present findings that the body weights of foetal and neonatal rats conceived and maintained at high altitude are normal, but that the weight of the placenta is increased, concur with reports of other investigators (Weihe, 1965;Nelson & Srebnik, 1970;Petro¬ poulos & Timiras, 1971, 19740) and reaffirm the presence of materno-placental adaptive responses to a hypoxic environment (Petropoulos & Timiras, 1971,19746). At the same time, the high incidence of neonatal mortality and the alterations in prenatal development specific to animals maintained at a high altitude reported here and in other experiments (Chiodi, 1964;Timiras, 1964;Kelley & Pace, 1968;Petropoulos & Timiras, 1974¿>) suggest that materno-placental protection is not complete and that foetal development is adversely affected by exposure to high altitude.…”

Section: Assessment Of Adrenocortical Functionsupporting

confidence: 94%

Alterations in Adrenal Growth and Corticosteroid Content in Foetal and Neonatal Rats Developing at High Altitude

Garvey¹,

Akana²,

Weisman³

et al. 1979

Journal of Endocrinology

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To study the effects of chronic maternal hypoxia on the growth and functional development of foetal and neonatal adrenal glands, Long-Evans rats were acclimatized to high altitude (3800 m) before mating and were maintained at this height throughout gestation. The body growth of the progeny at high altitude was essentially normal during the perinatal period, but adrenal weight and adrenocortical function showed marked differences from those of control rats maintained at sea level. The adrenal glands were larger in foetuses but smaller in neonates, compared with the adrenal glands of control animals maintained at sea level. Differences in the protein content of the adrenal glands between the two groups paralleled differences in adrenal weight. The concentration and content of corticosterone in the adrenal glands of both foetuses and neonates kept at high altitude were markedly lower than values in animals kept at sea level. The lower adrenal corticosterone content was not reflected in the concentration of the hormone in the peripheral plasma, since this was essentially the same at high altitude and at sea level in both mothers and perinatal animals. The reduction in the adrenal corticosterone content was accompanied by and may have resulted from, a reduction in the concentration of cytochrome P-450 in the adrenal tissue of foetuses maintained at high altitude. Possible explanations for the dichotomous results are discussed.

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Section: Assessment Of Adrenocortical Functionsupporting

confidence: 94%

Alterations in Adrenal Growth and Corticosteroid Content in Foetal and Neonatal Rats Developing at High Altitude

Garvey¹,

Akana²,

Weisman³

et al. 1979

Journal of Endocrinology

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“…Increased litter size in northern populations probably reflects shortening of the breeding season by the climate in northern latitudes compared to southern latitudes as shown by Smith & McGinnis (1968) for Peromyscus. In contrast, Weihe (1965) found that the number of young in rats was lower at 3,450 m than at 540 m a. s.l. The reproduction period and litter size (number of embryos in uterus) in common vole changed according to the climatic conditions in various altitudes (Figs 5,6).…”

Section: Reproduction Potential Of Microtus Arvalismentioning

confidence: 76%

Somatic characteristics and reproduction of common vole, Microtus arvalis (Microtus arvalis

Baláž

2010

Biologia

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Reproduction potential and biometry of somatic characteristics of the common vole Microtus arvalis were evaluated and discussed. The results were processed on the basis of an extensive material (2,171 individuals) from the whole territory of Slovakia (315 sites situated at altitudes from 100 to 1500 m above sea level). Among the somatic characteristics studied, the highest variability was found in body length and the smallest in hind foot length. Highly significant differences were also found between the foot length of adult males and females. Populations of M. arvalis at low altitudes were less numerous than at higher altitudes. Altitudinal differences in average embryo numbers in female uteri as well as differences in follicle length in males during the reproductive season were also observed.

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“…The pattern of slow prenatal development inferred from studies of birth weight continues during postnatal development. In high altitude rats this retarded growth results in a 30% reduction in adult body weight, even in cases where birth weights were equivalent to sea level rats (Weihe, 1965;Kelley and Pace, 1968;Petropoulos and Timiras, 1974). Studies in humans indicate that growth in body size during infancy, childhood and adolescence is delayed at high altitude when compared to growth in sea level counterparts (Frisancho, 1969;Baker, 1969;Frisancho and Baker, 1970;Haas, 1973;Boyce et al, 1974).…”

Section: Prenatal and Postnatal Growth In Body Sizementioning

confidence: 99%

Developmental adaptation to high altitude hypoxia

Frisancho

1977

Int J Biometeorol

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Experimental studies on animals and humans exposed to hypoxic stress have been reviewed. These data suggest that the influence of hypoxic stress, and the organism's response to it, are greater during growth than during adulthood. The organism's responses include alterations in the quantity and size of the alveolar units of the lungs, enlargement of the right ventricle of the heart, slower somatic growth as measured by birth weight and body size, increased aerobic capacity during maximal work, and greater control of ventilation. It is postulated that the organism is more sensitive to the influence of environmental factors during growth and development than during adulthood. Consequently, adaptive traits acquired during the developmental period have profound, long-term consequences, which are reflected in the physiological and morphological characteristics of the adult organism. It is concluded that the differences between the highland and lowland natives in their physiological performance and morphology are mostly due to adaptations acquired during the developmental period. Attention is called to the fact that the principle of developmental sensitivity and plasticity does not imply equally adaptive responses in all biological parameters. In other words, what we consider a deficiency in a given variable may actually reflect the indirect influence of the adaptive success of another variable.

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Influence of altitude and cold on pregnancy and lactation of rats fed on two different diets

Cited by 12 publications

References 10 publications

Alterations in Adrenal Growth and Corticosteroid Content in Foetal and Neonatal Rats Developing at High Altitude

Alterations in Adrenal Growth and Corticosteroid Content in Foetal and Neonatal Rats Developing at High Altitude

Somatic characteristics and reproduction of common vole, Microtus arvalis (Microtus arvalis

Developmental adaptation to high altitude hypoxia

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