Immunohistochemical localization of calbindins (28K and 9K) in the tissues of the baboon Papio ursinus

Abstract

An indirect immunoperoxidase procedure was used to detect the presence of calbindin-D28K and calbindin-D9K in the cerebellum, kidney, and duodenum of the baboon Papio ursinus. Antibodies to chick calbinding-D28K and to both rat and mouse calbindin-D9K were used. The cerebellum and kidney were shown to contain calbindin-D28K; the doudenum contained calbindin-D9K. In the cerebellum, positive staining was found in the Purkinje cells only; in the kidney, positive staining was found in the distal convoluted tubules, connecting tubules, and collecting tubules, extending deep into the medullary regions of the kidney. Staining in the duodenum was confined to the enterocytes of the villi, with no stain present in the crypt regions or goblet cells. Thus the baboon, a primate, contains the larger of the calbindins in both the cerebellum and kidney as does the human and monkey, but its distribution in the kidney is more generalized than that found in humans. The molecular weight of calbindin-D9K was found to be similar to that found in other animals. However, the calbindin-D28K from the baboon tissues appears to be slightly smaller than the protein found in other animals and may therefore be of similar size to the human calbindin-D28K (Mr 26,000).

Expression and Immunolocalization of Calcium Transport Proteins in the Canine Duodenum, Kidney, and Pancreas

“…In the duodenum, no immunoreactivity against calbindin D‐28k was detected in the dog. It is known from other species that the closely related protein calbindin D‐9k instead of calbindin D‐28k is responsible for intestinal intracellular calcium binding, and that calbindin D‐28k is not expressed in the duodenum (Opperman et al, 1990).…”

Endometrial expression of calbindin (CaBP)-d28k but not CaBP-d9k in primates implies evolutionary changes and functional redundancy of calbindins at implantation

“…This finding, however was not entirely surprising: previous studies in the uterus of Papio ursinus (baboon) have also shown no expression of the CaBP-d9k mRNA. This lack of expression was attributed to mutations in the 13 nucleotide long estrogen response element (ERE) at the 5 0 end of the baboon intron (Opperman et al 1990). In humans, the CaBP-d9k gene is 80% homologous to baboon CaBP-d9k and also contains the mutated ERE which would render the gene inactive in the uterus (Jeung et al 1992(Jeung et al , 1994.…”

“…Recent studies have demonstrated that despite the above mentioned differences between the two calbindins, both proteins are involved in modulating Ca 2þ absorption and regulating the transient cytosolic Ca 2þ concentration in a number of cells (Walters 1989, Mattson et al 1991, Schroder et al 1996, Schwaller et al 2002. Furthermore, they are often found co-localized in tissues (Opperman et al 1990, Shamley et al 1992, Berdal et al 1996, indicating complementary characteristics and overlapping functions.…”

Subterranean mole-rats naturally have an impoverished calciol status, yet synthesize calciol metabolites and calbindins

“…The presence of calbindins was determined using a modified indirect peroxidase immunocytochemical technique in fixed tissues as described by Opperman et al (24). Tissues were fixed in Bouins solution and were processed routinely through a graded series of alcohols, cleared in chloroform and embedded in paraplast (Histosec Pastilles, Merck, South Africa).…”