The city of Madison, Wisconsin addressed the issue and replaced all of their lead service lines, but there are still others that have yet to follow suit. While there are chemical methods that could help reduce the amount of lead in the water distributed, a permanent fix would be to replace the pipes completely. While the state may replace the pipes below ground, it will be up to the homeowners to replace the pipes on their property, at an average cost of $3,000. Experts say that if the city were to replace their pipes and the citizens were to keep the old pipes located within their homes, there would be a potential for more lead to dissolve into their drinking water.Collected rainwater from roof runoff used as potable water may contain lead, if there are lead contaminants on the roof or in the storage tank. The Australian Drinking Water Guidelines allow a maximum of 0.01 mg/L (10 ppb) lead in water.Lead wheel weights have been found to accumulate on roads and interstates and erode in traffic entering the water runoff through drains. Leaded fishing weights accumulate in rivers, streams, ponds, and lakes. Gasoline
Lead was first added to gasoline in 1923, as it helped keep car engines healthy. Automotive exhaust represented a major way for lead to be inhaled, invade the bloodstream and pass into the brain.The use of lead in gasoline peaked in the 1970s. By the next decade most high incomes countries prohibited the use of leaded petrol.
Pharmacology
Pharmacodynamics
Bremelanotide is a non-selective agonist of the melanocortin receptors, MC1 through MC5 (with the exception of MC2, the receptor of ACTH), but acting primarily as an MC3 and MC4 receptor agonist. Pharmacokinetics
The bioavailability of bremelanotide with subcutaneous injection is about 100%. Following a subcutaneous injection of bremelanotide, maximal levels occur after about one hour, with a range of 0.5 to 1.0 hours. The plasma protein binding of bremelanotide is 21%. Bremelanotide is metabolized via hydrolysis of its peptide bonds. The elimination half-life of bremelanotide is 2.7 hours, with a range of 1.9 to 4.0 hours. Bremelanotide is excreted 64.8% in urine and 22.8% in feces. Chemistry
Bremelanotide is a cyclic heptapeptide lactam analogue of α-melanocyte-stimulating hormone (α-MSH). It has the amino acid sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, and is also known as cyclo-[Nle4,Asp5,D-Phe7,Lys10]α-MSH-(4-10). Bremelanotide is an active metabolite of melanotan II that lacks the C-terminal amide group.Aside from melanotan II and endogenous melanocyte-stimulating hormones like α-MSH, other peptide analogues of the same family as bremelanotide include afamelanotide (NDP-α-MSH), modimelanotide, and setmelanotide. History
Studies in the early 1960s showed that administration of α-MSH caused sexual arousal in rats, sparking interest in α-MSH. In the 1980s, scientists at University of Arizona began developing α-MSH and analogs as potential sunless tanning agents.