Perturbations in blood Ca(2)+ do not affect the activity of rat stomach enterochromaffin-like cells.
BACKGROUND
Gastrin stimulates uptake of Ca(2)+ into bone and causes transient hypocalcemia, possibly by releasing a peptide hormone from enterochromaffin-like (ECL) cells, which are histamine- and peptidehormone-producing cells in the acid-producing part of the stomach. However, if ECL cells secrete a calciotropic hormone, it is to be expected that their activity is affected by the serum Ca(2)+ concentration.


METHODS
Food-deprived male rats were infused with human (Leu)15-gastrin-17 and/or ethylenediamine-tetraacetic acid and CaCl(2). The blood Ca(2)+ level was monitored throughout the experiments (3 h), and the serum concentrations of gastrin, parathyroid hormone, and calcitonin were measured at death. The activity of the ECL cells was assessed by measuring the histidine decarboxylase (HDC) activity.


RESULTS
Gastrin produced the expected increase in HDC activity, but neither hyper- nor hypo-calcemia affected the RDC activity of either hypo- or hyper-gastrinemic rats.


CONCLUSIONS
Perturbations in blood Ca(2)+ do not seem to affect ECL cells, which is at odds with the view that ECL cells harbor a calciotropic hormone.
Hakanson
R
R
Dept. of Pharmacology, University of Lund, Lund, Sweden.
Gagnemo-Persson
R
R
Surve
V V
VV
D000818:Animals; D002116:Calcitonin / Q000097:blood; D002118:Calcium / Q000097:blood*; D002122:Calcium Chloride / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004759:Enterochromaffin Cells / Q000378:metabolism*; D004789:Enzyme Activation; D005753:Gastric Mucosa / Q000166:cytology*; D005755:Gastrins / Q000097:blood / Q000494:pharmacology; D006640:Histidine Decarboxylase / Q000378:metabolism; D006728:Hormones / Q000494:pharmacology; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley
D005755:Gastrins; D006728:Hormones; D010281:Parathyroid Hormone; C013550:gastrin 17; D002116:Calcitonin; D004492:Edetic Acid; D006640:Histidine Decarboxylase; D002122:Calcium Chloride; D002118:Calcium