Renal intraspecific variation along an aridity gradient detected by new renal indices in a desert herbivorous rodent

PATRICIA TEJO; GABRIELA B. DÍAZ ISENRATH; NATALIA ANDINO; CARLOS E. BORGHI

JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL GENETICS AND PHYSIOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2014 vol. 321 p. 348 - 356

1932-5223

Mammals that live in arid and semi‐arid environments in South America present physiological mechanisms that enable them to conserve water. Body water is lost through the kidneys, lungs, skin, and intestines. Regarding renal adaptation for water conservation, several indices have been used to estimate the capacity of the kidneys to produce a maximum urine concentration. Most studies were conducted at an inter‐specific level, with only few performed at the intraspecific level. In this work, we compare renal function and morphology amongfive populations of Southern mountain cavy,Microcavia australis, present along an aridity gradient. We hypothesized that individuals from drier zones would present morphological and functional renal modifications that imply a greater capability to conserve body water. These features were studied considering the classical indices (RMT, PMT, PMA, and RMA) and three new indices that consider area measurements; the latter showed to be more adequate to reflect intraspecific differences. Our results suggest that the morphological modifications of kidneys, that is, the greater areas of renal inner medulla, would be related to the aridity gradient where populations of Southern mountain cavy occur.