{'fraction_non_alphanumeric': 0.0325105358217941, 'fraction_numerical': 0.019867549668874173, 'mean_word_length': 4.731034482758621, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Creation of the 5-hydroxytryptamine receptor 7 knockout (5-HT7KO) Rat as a Tool for Cardiovascular Research.

We created a 5-HT7 receptor global knockout (KO) rat, on a Sprague-Dawley background, using CRISPR-Cas9 technology, for use in cardiovascular physiology studies focused on blood pressure regulation. A stable line carrying indels in exons 1 and 2 of the rat Htr7locus was established and validated. Surprisingly, 5-HT7receptor mRNA was still present in the KO rat. However, extensive cDNA and genomic sequencing of KO tissues confirmed an 11 bp deletion in exon 1 and 4 bp deletion in exon 2. The exon 1 deletion resulted in a frameshifted mRNA sequence coding for a non-functional protein. While the Htr1Blocus was a potential off-target for the gRNAs designed for exon 2 of Htr7, there were no off-target sequence changes at this locus in the originating founder. When the F2 generation of KO was compared to WT counterparts, neither the male nor female KO rats were different in body size, fat weights, or mass of organs (kidney, heart and brain) important to blood pressure. Females were smaller in mass than their counterpart males. Clinical measures of plasma from non-fasted rats revealed largely similar values, comparing WT and KO, of glucose, blood urea nitrogen, creatinine, phosphate, calcium, and albumin to name a few. Loss of a functional 5-HT7receptor was validated by the complete loss of relaxation to the 5-HT1/7receptor agonist 5-carboxamidotryptamine (5-CT) in the isolated abdominal vena cava. This newly created 5-HT7 receptor KO rat will be of use to investigate the importance of the 5-HT7receptor in blood pressure regulation.