The expression of histamine H₄ receptor mRNA in the skin and other tissues of normal dogs

Abstract

The histamine 4 (H(4)) receptor was first cloned and characterized in 2000 using the human H(3) receptor DNA sequence. The H(4) receptor has been shown to participate in various aspects of inflammation, such as chemotaxis, upregulation of adhesion molecule expression and modulation of cytokine secretion. The primary goal of this study was to determine whether H(4) receptor mRNA is expressed in normal canine skin by performing an RT-PCR. An additional goal was to determine the expression of this receptor in the colon, liver, spleen and kidney. Tissues were collected from five healthy, young-adult pit bull dogs. Samples were immediately placed in RNAlater(®) solution and stored at -20°C until processed. The amplified products in all skin samples in addition to the colon, liver, spleen and kidney (variable expression) had the expected size of 400-500 bp. The sequenced amplicons matched the National Center for Biotechnology Information published sequence for the canine H(4) receptor. The study results showed that canine normal skin expresses the H(4) receptor mRNA. Further studies using immunohistochemistry should be conducted to demonstrate the expression of the H(4) receptor at the protein level and to localize the expression of this receptor in the skin.

Overexpression of histamine H4 receptors in the kidney of diabetic rat

“…A very low level of H 4 receptor mRNA has been reported in the kidney of dog, monkey, rat, mouse, guinea pig and pig [14][15][16][17][18]. Despite the demonstration of an increasing histamine release in diabetic kidney, there is no evidence for the involvement of H 4 receptor expression in the diabetes-related kidney disease.…”

“…Interestingly, although expression differences were observed among species [14,15,17,18,34], the similar tissue distribution in different mammals indicates conserved and comparable physiological roles of the H 4 receptor across species. Therefore, we could speculate similar roles in humans.…”

“…Later, the constitutive, but very low H 4 receptor gene expression, was confirmed in different species [14][15][16][17][18]36];…”

Histamine receptor expression in human renal tubules: a comparative pharmacological evaluation

“…Recently, a possible role for H 4 R has been suggested by our research group [14]. While a very low mRNA level of the latest discovered histamine receptor has been reported in the kidney of dog, monkey, rat, mouse, guinea pig and pig [15][16][17][18][19][20], in 2013 we demonstrated the presence of H 4 R in resident renal cells of the loop of Henlé!and its profound upregulation in the kidney of diabetic rats [14]. Notably, these data provide the first basis to hypothesize a possible involvement of H 4 R in the onset/progression of diabetes-associated renal disease.…”

Histamine Receptor Expression in the Gastrointestinal Tract of Dogs

“…Moreover, H3R has been demonstrated to be functionally absent from the canine colon, and this suggests H3R to be of minor importance for gastrointestinal function in many animals species including dogs (Rangachari and Prior, 1994). In recent studies, expression of H4R mRNA was demonstrated in various canine tissues including those of the small intestine and colon (Jiang et al, 2008;Eisenschenk et al, 2011). The expression and distribution of H1R, H2R and H4R in canine tissues at protein level, however, are unknown.…”