Histamine stimulate the secretion of:
According to Davenport theory, hydrochloric acid secretion is an active process in the canaliculi of parietal cells in gastric glands, utilising the energy derived from oxidation of glucose.
Factors stimulating the secretion of HCl:

Gastrin
Histamine
Vagal stimulation

Factors inhibiting the secretion of HCl:

Secretin
Gastric inhibitory polypeptide
Peptide YY
Gastrin by stomach
Pancreatic enzymes
HCl by stomach
Amylase by salivary gland